Adding .clang-tidy readability-braces-around-statements option.

clang-tidy automatic changes. NO manual changes.

.clang-tidy

@@ -31,6 +31,7 @@ modernize-use-override,
 modernize-use-using,
 *performance*,
 readability-avoid-const-params-in-decls,
+readability-braces-around-statements,
 readability-const-return-type,
 readability-container-size-empty,
 readability-delete-null-pointer,

include/pybind11/attr.h

@@ -330,11 +330,13 @@ struct type_record {
 
         bases.append((PyObject *) base_info->type);
 
-        if (base_info->type->tp_dictoffset != 0)
+        if (base_info->type->tp_dictoffset != 0) {
             dynamic_attr = true;
+        }
 
-        if (caster)
+        if (caster) {
             base_info->implicit_casts.emplace_back(type, caster);
+        }
     }
 };
 
@@ -410,13 +412,16 @@ template <> struct process_attribute<is_new_style_constructor> : process_attribu
 };
 
 inline void check_kw_only_arg(const arg &a, function_record *r) {
-    if (r->args.size() > r->nargs_pos && (!a.name || a.name[0] == '\0'))
-        pybind11_fail("arg(): cannot specify an unnamed argument after a kw_only() annotation or args() argument");
+    if (r->args.size() > r->nargs_pos && (!a.name || a.name[0] == '\0')) {
+        pybind11_fail("arg(): cannot specify an unnamed argument after a kw_only() annotation or "
+                      "args() argument");
+    }
 }
 
 inline void append_self_arg_if_needed(function_record *r) {
-    if (r->is_method && r->args.empty())
-        r->args.emplace_back("self", nullptr, handle(), /*convert=*/ true, /*none=*/ false);
+    if (r->is_method && r->args.empty()) {
+        r->args.emplace_back("self", nullptr, handle(), /*convert=*/true, /*none=*/false);
+    }
 }
 
 /// Process a keyword argument attribute (*without* a default value)
@@ -432,8 +437,10 @@ template <> struct process_attribute<arg> : process_attribute_default<arg> {
 /// Process a keyword argument attribute (*with* a default value)
 template <> struct process_attribute<arg_v> : process_attribute_default<arg_v> {
     static void init(const arg_v &a, function_record *r) {
-        if (r->is_method && r->args.empty())
-            r->args.emplace_back("self", /*descr=*/ nullptr, /*parent=*/ handle(), /*convert=*/ true, /*none=*/ false);
+        if (r->is_method && r->args.empty()) {
+            r->args.emplace_back(
+                "self", /*descr=*/nullptr, /*parent=*/handle(), /*convert=*/true, /*none=*/false);
+        }
 
         if (!a.value) {
 #if !defined(NDEBUG)
@@ -466,8 +473,10 @@ template <> struct process_attribute<arg_v> : process_attribute_default<arg_v> {
 template <> struct process_attribute<kw_only> : process_attribute_default<kw_only> {
     static void init(const kw_only &, function_record *r) {
         append_self_arg_if_needed(r);
-        if (r->has_args && r->nargs_pos != static_cast<std::uint16_t>(r->args.size()))
-            pybind11_fail("Mismatched args() and kw_only(): they must occur at the same relative argument location (or omit kw_only() entirely)");
+        if (r->has_args && r->nargs_pos != static_cast<std::uint16_t>(r->args.size())) {
+            pybind11_fail("Mismatched args() and kw_only(): they must occur at the same relative "
+                          "argument location (or omit kw_only() entirely)");
+        }
         r->nargs_pos = static_cast<std::uint16_t>(r->args.size());
     }
 };
@@ -477,8 +486,9 @@ template <> struct process_attribute<pos_only> : process_attribute_default<pos_o
     static void init(const pos_only &, function_record *r) {
         append_self_arg_if_needed(r);
         r->nargs_pos_only = static_cast<std::uint16_t>(r->args.size());
-        if (r->nargs_pos_only > r->nargs_pos)
+        if (r->nargs_pos_only > r->nargs_pos) {
             pybind11_fail("pos_only(): cannot follow a py::args() argument");
+        }
             // It also can't follow a kw_only, but a static_assert in pybind11.h checks that
     }
 };

include/pybind11/buffer_info.h

@@ -19,9 +19,11 @@ PYBIND11_NAMESPACE_BEGIN(detail)
 inline std::vector<ssize_t> c_strides(const std::vector<ssize_t> &shape, ssize_t itemsize) {
     auto ndim = shape.size();
     std::vector<ssize_t> strides(ndim, itemsize);
-    if (ndim > 0)
-        for (size_t i = ndim - 1; i > 0; --i)
+    if (ndim > 0) {
+        for (size_t i = ndim - 1; i > 0; --i) {
             strides[i - 1] = strides[i] * shape[i];
+        }
+    }
     return strides;
 }
 
@@ -29,8 +31,9 @@ inline std::vector<ssize_t> c_strides(const std::vector<ssize_t> &shape, ssize_t
 inline std::vector<ssize_t> f_strides(const std::vector<ssize_t> &shape, ssize_t itemsize) {
     auto ndim = shape.size();
     std::vector<ssize_t> strides(ndim, itemsize);
-    for (size_t i = 1; i < ndim; ++i)
+    for (size_t i = 1; i < ndim; ++i) {
         strides[i] = strides[i - 1] * shape[i - 1];
+    }
     return strides;
 }
 
@@ -53,10 +56,12 @@ struct buffer_info {
                 detail::any_container<ssize_t> shape_in, detail::any_container<ssize_t> strides_in, bool readonly=false)
     : ptr(ptr), itemsize(itemsize), size(1), format(format), ndim(ndim),
       shape(std::move(shape_in)), strides(std::move(strides_in)), readonly(readonly) {
-        if (ndim != (ssize_t) shape.size() || ndim != (ssize_t) strides.size())
+        if (ndim != (ssize_t) shape.size() || ndim != (ssize_t) strides.size()) {
             pybind11_fail("buffer_info: ndim doesn't match shape and/or strides length");
-        for (size_t i = 0; i < (size_t) ndim; ++i)
+        }
+        for (size_t i = 0; i < (size_t) ndim; ++i) {
             size *= shape[i];
+        }
     }
 
     template <typename T>

include/pybind11/cast.h

@@ -60,8 +60,10 @@ public:
     static constexpr auto name = caster_t::name;
     static handle cast(const std::reference_wrapper<type> &src, return_value_policy policy, handle parent) {
         // It is definitely wrong to take ownership of this pointer, so mask that rvp
-        if (policy == return_value_policy::take_ownership || policy == return_value_policy::automatic)
+        if (policy == return_value_policy::take_ownership
+            || policy == return_value_policy::automatic) {
             policy = return_value_policy::automatic_reference;
+        }
         return caster_t::cast(&src.get(), policy, parent);
     }
     template <typename T> using cast_op_type = std::reference_wrapper<type>;
@@ -112,8 +114,9 @@ public:
     bool load(handle src, bool convert) {
         py_type py_value;
 
-        if (!src)
+        if (!src) {
             return false;
+        }
 
 #if !defined(PYPY_VERSION)
         auto index_check = [](PyObject *o) { return PyIndex_Check(o); };
@@ -124,10 +127,11 @@ public:
 #endif
 
         if (std::is_floating_point<T>::value) {
-            if (convert || PyFloat_Check(src.ptr()))
+            if (convert || PyFloat_Check(src.ptr())) {
                 py_value = (py_type) PyFloat_AsDouble(src.ptr());
-            else
+            } else {
                 return false;
+            }
         } else if (PyFloat_Check(src.ptr())
                    || (!convert && !PYBIND11_LONG_CHECK(src.ptr()) && !index_check(src.ptr()))) {
             return false;
@@ -214,8 +218,9 @@ public:
 template<typename T> struct void_caster {
 public:
     bool load(handle src, bool) {
-        if (src && src.is_none())
+        if (src && src.is_none()) {
             return true;
+        }
         return false;
     }
     static handle cast(T, return_value_policy /* policy */, handle /* parent */) {
@@ -257,8 +262,9 @@ public:
     }
 
     static handle cast(const void *ptr, return_value_policy /* policy */, handle /* parent */) {
-        if (ptr)
+        if (ptr) {
             return capsule(ptr).release();
+        }
         return none().inc_ref();
     }
 
@@ -274,7 +280,9 @@ template <> class type_caster<std::nullptr_t> : public void_caster<std::nullptr_
 template <> class type_caster<bool> {
 public:
     bool load(handle src, bool convert) {
-        if (!src) return false;
+        if (!src) {
+            return false;
+        }
         if (src.ptr() == Py_True) {
             value = true;
             return true;
@@ -391,8 +399,9 @@ template <typename StringType, bool IsView = false> struct string_caster {
         value = StringType(buffer, length);
 
         // If we're loading a string_view we need to keep the encoded Python object alive:
-        if (IsView)
+        if (IsView) {
             loader_life_support::add_patient(utfNbytes);
+        }
 
         return true;
     }
@@ -401,7 +410,9 @@ template <typename StringType, bool IsView = false> struct string_caster {
         const char *buffer = reinterpret_cast<const char *>(src.data());
         auto nbytes = ssize_t(src.size() * sizeof(CharT));
         handle s = decode_utfN(buffer, nbytes);
-        if (!s) throw error_already_set();
+        if (!s) {
+            throw error_already_set();
+        }
         return s;
     }
 
@@ -463,10 +474,14 @@ template <typename CharT> struct type_caster<CharT, enable_if_t<is_std_char_type
     CharT one_char = 0;
 public:
     bool load(handle src, bool convert) {
-        if (!src) return false;
+        if (!src) {
+            return false;
+        }
         if (src.is_none()) {
             // Defer accepting None to other overloads (if we aren't in convert mode):
-            if (!convert) return false;
+            if (!convert) {
+                return false;
+            }
             none = true;
             return true;
         }
@@ -474,14 +489,18 @@ public:
     }
 
     static handle cast(const CharT *src, return_value_policy policy, handle parent) {
-        if (src == nullptr) return pybind11::none().inc_ref();
+        if (src == nullptr) {
+            return pybind11::none().inc_ref();
+        }
         return StringCaster::cast(StringType(src), policy, parent);
     }
 
     static handle cast(CharT src, return_value_policy policy, handle parent) {
         if (std::is_same<char, CharT>::value) {
             handle s = PyUnicode_DecodeLatin1((const char *) &src, 1, nullptr);
-            if (!s) throw error_already_set();
+            if (!s) {
+                throw error_already_set();
+            }
             return s;
         }
         return StringCaster::cast(StringType(1, src), policy, parent);
@@ -491,13 +510,15 @@ public:
         return none ? nullptr : const_cast<CharT *>(static_cast<StringType &>(str_caster).c_str());
     }
     explicit operator CharT &() {
-        if (none)
+        if (none) {
             throw value_error("Cannot convert None to a character");
+        }
 
         auto &value = static_cast<StringType &>(str_caster);
         size_t str_len = value.size();
-        if (str_len == 0)
+        if (str_len == 0) {
             throw value_error("Cannot convert empty string to a character");
+        }
 
         // If we're in UTF-8 mode, we have two possible failures: one for a unicode character that
         // is too high, and one for multiple unicode characters (caught later), so we need to figure
@@ -531,12 +552,14 @@ public:
         // string was too long" error).
         else if (PYBIND11_SILENCE_MSVC_C4127(StringCaster::UTF_N == 16) && str_len == 2) {
             one_char = static_cast<CharT>(value[0]);
-            if (one_char >= 0xD800 && one_char < 0xE000)
+            if (one_char >= 0xD800 && one_char < 0xE000) {
                 throw value_error("Character code point not in range(0x10000)");
+            }
         }
 
-        if (str_len != 1)
+        if (str_len != 1) {
             throw value_error("Expected a character, but multi-character string found");
+        }
 
         one_char = value[0];
         return one_char;
@@ -554,11 +577,13 @@ template <template<typename...> class Tuple, typename... Ts> class tuple_caster
 public:
 
     bool load(handle src, bool convert) {
-        if (!isinstance<sequence>(src))
+        if (!isinstance<sequence>(src)) {
             return false;
+        }
         const auto seq = reinterpret_borrow<sequence>(src);
-        if (seq.size() != size)
+        if (seq.size() != size) {
             return false;
+        }
         return load_impl(seq, convert, indices{});
     }
 
@@ -570,7 +595,9 @@ public:
     // copied from the PYBIND11_TYPE_CASTER macro
     template <typename T>
     static handle cast(T *src, return_value_policy policy, handle parent) {
-        if (!src) return none().release();
+        if (!src) {
+            return none().release();
+        }
         if (policy == return_value_policy::take_ownership) {
             auto h = cast(std::move(*src), policy, parent);
             delete src;
@@ -597,8 +624,9 @@ protected:
     template <size_t... Is>
     bool load_impl(const sequence &seq, bool convert, index_sequence<Is...>) {
 #ifdef __cpp_fold_expressions
-        if ((... || !std::get<Is>(subcasters).load(seq[Is], convert)))
+        if ((... || !std::get<Is>(subcasters).load(seq[Is], convert))) {
             return false;
+        }
 #else
         for (bool r : {std::get<Is>(subcasters).load(seq[Is], convert)...})
             if (!r)
@@ -615,13 +643,16 @@ protected:
         std::array<object, size> entries{{
             reinterpret_steal<object>(make_caster<Ts>::cast(std::get<Is>(std::forward<T>(src)), policy, parent))...
         }};
-        for (const auto &entry: entries)
-            if (!entry)
+        for (const auto &entry : entries) {
+            if (!entry) {
                 return handle();
+            }
+        }
         tuple result(size);
         int counter = 0;
-        for (auto & entry: entries)
+        for (auto &entry : entries) {
             PyTuple_SET_ITEM(result.ptr(), counter++, entry.release().ptr());
+        }
         return result.release();
     }
 
@@ -676,8 +707,9 @@ public:
 protected:
     friend class type_caster_generic;
     void check_holder_compat() {
-        if (typeinfo->default_holder)
+        if (typeinfo->default_holder) {
             throw cast_error("Unable to load a custom holder type from a default-holder instance");
+        }
     }
 
     bool load_value(value_and_holder &&v_h) {
@@ -793,8 +825,9 @@ struct pyobject_caster {
             return true;
         }
 #endif
-        if (!isinstance<type>(src))
+        if (!isinstance<type>(src)) {
             return false;
+        }
         value = reinterpret_borrow<type>(src);
         return true;
     }
@@ -901,12 +934,14 @@ template <typename T, detail::enable_if_t<!detail::is_pyobject<T>::value, int> =
 object cast(T &&value, return_value_policy policy = return_value_policy::automatic_reference,
             handle parent = handle()) {
     using no_ref_T = typename std::remove_reference<T>::type;
-    if (policy == return_value_policy::automatic)
+    if (policy == return_value_policy::automatic) {
         policy = std::is_pointer<no_ref_T>::value ? return_value_policy::take_ownership :
                  std::is_lvalue_reference<T>::value ? return_value_policy::copy : return_value_policy::move;
-    else if (policy == return_value_policy::automatic_reference)
-        policy = std::is_pointer<no_ref_T>::value ? return_value_policy::reference :
-                 std::is_lvalue_reference<T>::value ? return_value_policy::copy : return_value_policy::move;
+    } else if (policy == return_value_policy::automatic_reference) {
+        policy = std::is_pointer<no_ref_T>::value     ? return_value_policy::reference
+                 : std::is_lvalue_reference<T>::value ? return_value_policy::copy
+                                                      : return_value_policy::move;
+    }
     return reinterpret_steal<object>(detail::make_caster<T>::cast(std::forward<T>(value), policy, parent));
 }
 
@@ -939,8 +974,9 @@ template <typename T> detail::enable_if_t<detail::move_always<T>::value, T> cast
     return move<T>(std::move(object));
 }
 template <typename T> detail::enable_if_t<detail::move_if_unreferenced<T>::value, T> cast(object &&object) {
-    if (object.ref_count() > 1)
+    if (object.ref_count() > 1) {
         return cast<T>(object);
+    }
     return move<T>(std::move(object));
 }
 template <typename T> detail::enable_if_t<detail::move_never<T>::value, T> cast(object &&object) {
@@ -1018,8 +1054,9 @@ template <return_value_policy policy = return_value_policy::automatic_reference,
     }
     tuple result(size);
     int counter = 0;
-    for (auto &arg_value : args)
+    for (auto &arg_value : args) {
         PyTuple_SET_ITEM(result.ptr(), counter++, arg_value.release().ptr());
+    }
     return result;
 }
 
@@ -1231,8 +1268,9 @@ public:
     /// Call a Python function and pass the collected arguments
     object call(PyObject *ptr) const {
         PyObject *result = PyObject_CallObject(ptr, m_args.ptr());
-        if (!result)
+        if (!result) {
             throw error_already_set();
+        }
         return reinterpret_steal<object>(result);
     }
 
@@ -1264,8 +1302,9 @@ public:
     /// Call a Python function and pass the collected arguments
     object call(PyObject *ptr) const {
         PyObject *result = PyObject_Call(ptr, m_args.ptr(), m_kwargs.ptr());
-        if (!result)
+        if (!result) {
             throw error_already_set();
+        }
         return reinterpret_steal<object>(result);
     }
 
@@ -1285,8 +1324,9 @@ private:
     }
 
     void process(list &args_list, detail::args_proxy ap) {
-        for (auto a : ap)
+        for (auto a : ap) {
             args_list.append(a);
+        }
     }
 
     void process(list &/*args_list*/, arg_v a) {
@@ -1315,8 +1355,9 @@ private:
     }
 
     void process(list &/*args_list*/, detail::kwargs_proxy kp) {
-        if (!kp)
+        if (!kp) {
             return;
+        }
         for (auto k : reinterpret_borrow<dict>(kp)) {
             if (m_kwargs.contains(k.first)) {
 #if defined(NDEBUG)

include/pybind11/chrono.h

@@ -46,7 +46,9 @@ public:
         // Lazy initialise the PyDateTime import
         if (!PyDateTimeAPI) { PyDateTime_IMPORT; }
 
-        if (!src) return false;
+        if (!src) {
+            return false;
+        }
         // If invoked with datetime.delta object
         if (PyDelta_Check(src.ptr())) {
             value = type(duration_cast<duration<rep, period>>(
@@ -124,7 +126,9 @@ public:
         // Lazy initialise the PyDateTime import
         if (!PyDateTimeAPI) { PyDateTime_IMPORT; }
 
-        if (!src) return false;
+        if (!src) {
+            return false;
+        }
 
         std::tm cal;
         microseconds msecs;
@@ -156,8 +160,9 @@ public:
             cal.tm_year  = 70;  // earliest available date for Python's datetime
             cal.tm_isdst = -1;
             msecs        = microseconds(PyDateTime_TIME_GET_MICROSECOND(src.ptr()));
+        } else {
+            return false;
         }
-        else return false;
 
         value = time_point_cast<Duration>(system_clock::from_time_t(std::mktime(&cal)) + msecs);
         return true;
@@ -173,8 +178,9 @@ public:
         // (cfr. https://github.com/pybind/pybind11/issues/2417)
         using us_t = duration<int, std::micro>;
         auto us = duration_cast<us_t>(src.time_since_epoch() % seconds(1));
-        if (us.count() < 0)
+        if (us.count() < 0) {
             us += seconds(1);
+        }
 
         // Subtract microseconds BEFORE `system_clock::to_time_t`, because:
         // > If std::time_t has lower precision, it is implementation-defined whether the value is rounded or truncated.
@@ -183,8 +189,9 @@ public:
 
         std::tm localtime;
         std::tm *localtime_ptr = localtime_thread_safe(&tt, &localtime);
-        if (!localtime_ptr)
+        if (!localtime_ptr) {
             throw cast_error("Unable to represent system_clock in local time");
+        }
         return PyDateTime_FromDateAndTime(localtime.tm_year + 1900,
                                           localtime.tm_mon + 1,
                                           localtime.tm_mday,

include/pybind11/complex.h

@@ -42,10 +42,12 @@ template <typename T> struct is_fmt_numeric<std::complex<T>, detail::enable_if_t
 template <typename T> class type_caster<std::complex<T>> {
 public:
     bool load(handle src, bool convert) {
-        if (!src)
+        if (!src) {
             return false;
-        if (!convert && !PyComplex_Check(src.ptr()))
+        }
+        if (!convert && !PyComplex_Check(src.ptr())) {
             return false;
+        }
         Py_complex result = PyComplex_AsCComplex(src.ptr());
         if (result.real == -1.0 && PyErr_Occurred()) {
             PyErr_Clear();

include/pybind11/detail/class.h

@@ -66,8 +66,9 @@ inline PyTypeObject *make_static_property_type() {
        garbage collector (the GC will call type_traverse(), which will in
        turn find the newly constructed type in an invalid state) */
     auto heap_type = (PyHeapTypeObject *) PyType_Type.tp_alloc(&PyType_Type, 0);
-    if (!heap_type)
+    if (!heap_type) {
         pybind11_fail("make_static_property_type(): error allocating type!");
+    }
 
     heap_type->ht_name = name_obj.inc_ref().ptr();
 #ifdef PYBIND11_BUILTIN_QUALNAME
@@ -81,8 +82,9 @@ inline PyTypeObject *make_static_property_type() {
     type->tp_descr_get = pybind11_static_get;
     type->tp_descr_set = pybind11_static_set;
 
-    if (PyType_Ready(type) < 0)
+    if (PyType_Ready(type) < 0) {
         pybind11_fail("make_static_property_type(): failure in PyType_Ready()!");
+    }
 
     setattr((PyObject *) type, "__module__", str("pybind11_builtins"));
     PYBIND11_SET_OLDPY_QUALNAME(type, name_obj);
@@ -209,19 +211,21 @@ extern "C" inline void pybind11_meta_dealloc(PyObject *obj) {
         auto tindex = std::type_index(*tinfo->cpptype);
         internals.direct_conversions.erase(tindex);
 
-        if (tinfo->module_local)
+        if (tinfo->module_local) {
             get_local_internals().registered_types_cpp.erase(tindex);
-        else
+        } else {
             internals.registered_types_cpp.erase(tindex);
+        }
         internals.registered_types_py.erase(tinfo->type);
 
         // Actually just `std::erase_if`, but that's only available in C++20
         auto &cache = internals.inactive_override_cache;
         for (auto it = cache.begin(), last = cache.end(); it != last; ) {
-            if (it->first == (PyObject *) tinfo->type)
+            if (it->first == (PyObject *) tinfo->type) {
                 it = cache.erase(it);
-            else
+            } else {
                 ++it;
+            }
         }
 
         delete tinfo;
@@ -242,8 +246,9 @@ inline PyTypeObject* make_default_metaclass() {
        garbage collector (the GC will call type_traverse(), which will in
        turn find the newly constructed type in an invalid state) */
     auto heap_type = (PyHeapTypeObject *) PyType_Type.tp_alloc(&PyType_Type, 0);
-    if (!heap_type)
+    if (!heap_type) {
         pybind11_fail("make_default_metaclass(): error allocating metaclass!");
+    }
 
     heap_type->ht_name = name_obj.inc_ref().ptr();
 #ifdef PYBIND11_BUILTIN_QUALNAME
@@ -264,8 +269,9 @@ inline PyTypeObject* make_default_metaclass() {
 
     type->tp_dealloc = pybind11_meta_dealloc;
 
-    if (PyType_Ready(type) < 0)
+    if (PyType_Ready(type) < 0) {
         pybind11_fail("make_default_metaclass(): failure in PyType_Ready()!");
+    }
 
     setattr((PyObject *) type, "__module__", str("pybind11_builtins"));
     PYBIND11_SET_OLDPY_QUALNAME(type, name_obj);
@@ -283,8 +289,9 @@ inline void traverse_offset_bases(void *valueptr, const detail::type_info *tinfo
             for (auto &c : parent_tinfo->implicit_casts) {
                 if (c.first == tinfo->cpptype) {
                     auto *parentptr = c.second(valueptr);
-                    if (parentptr != valueptr)
+                    if (parentptr != valueptr) {
                         f(parentptr, self);
+                    }
                     traverse_offset_bases(parentptr, parent_tinfo, self, f);
                     break;
                 }
@@ -311,14 +318,16 @@ inline bool deregister_instance_impl(void *ptr, instance *self) {
 
 inline void register_instance(instance *self, void *valptr, const type_info *tinfo) {
     register_instance_impl(valptr, self);
-    if (!tinfo->simple_ancestors)
+    if (!tinfo->simple_ancestors) {
         traverse_offset_bases(valptr, tinfo, self, register_instance_impl);
+    }
 }
 
 inline bool deregister_instance(instance *self, void *valptr, const type_info *tinfo) {
     bool ret = deregister_instance_impl(valptr, self);
-    if (!tinfo->simple_ancestors)
+    if (!tinfo->simple_ancestors) {
         traverse_offset_bases(valptr, tinfo, self, deregister_instance_impl);
+    }
     return ret;
 }
 
@@ -377,8 +386,9 @@ inline void clear_patients(PyObject *self) {
     auto patients = std::move(pos->second);
     internals.patients.erase(pos);
     instance->has_patients = false;
-    for (PyObject *&patient : patients)
+    for (PyObject *&patient : patients) {
         Py_CLEAR(patient);
+    }
 }
 
 /// Clears all internal data from the instance and removes it from registered instances in
@@ -392,25 +402,32 @@ inline void clear_instance(PyObject *self) {
 
             // We have to deregister before we call dealloc because, for virtual MI types, we still
             // need to be able to get the parent pointers.
-            if (v_h.instance_registered() && !deregister_instance(instance, v_h.value_ptr(), v_h.type))
-                pybind11_fail("pybind11_object_dealloc(): Tried to deallocate unregistered instance!");
+            if (v_h.instance_registered()
+                && !deregister_instance(instance, v_h.value_ptr(), v_h.type)) {
+                pybind11_fail(
+                    "pybind11_object_dealloc(): Tried to deallocate unregistered instance!");
+            }
 
-            if (instance->owned || v_h.holder_constructed())
+            if (instance->owned || v_h.holder_constructed()) {
                 v_h.type->dealloc(v_h);
+            }
         }
     }
     // Deallocate the value/holder layout internals:
     instance->deallocate_layout();
 
-    if (instance->weakrefs)
+    if (instance->weakrefs) {
         PyObject_ClearWeakRefs(self);
+    }
 
     PyObject **dict_ptr = _PyObject_GetDictPtr(self);
-    if (dict_ptr)
+    if (dict_ptr) {
         Py_CLEAR(*dict_ptr);
+    }
 
-    if (instance->has_patients)
+    if (instance->has_patients) {
         clear_patients(self);
+    }
 }
 
 /// Instance destructor function for all pybind11 types. It calls `type_info.dealloc`
@@ -448,8 +465,9 @@ inline PyObject *make_object_base_type(PyTypeObject *metaclass) {
        garbage collector (the GC will call type_traverse(), which will in
        turn find the newly constructed type in an invalid state) */
     auto heap_type = (PyHeapTypeObject *) metaclass->tp_alloc(metaclass, 0);
-    if (!heap_type)
+    if (!heap_type) {
         pybind11_fail("make_object_base_type(): error allocating type!");
+    }
 
     heap_type->ht_name = name_obj.inc_ref().ptr();
 #ifdef PYBIND11_BUILTIN_QUALNAME
@@ -469,8 +487,9 @@ inline PyObject *make_object_base_type(PyTypeObject *metaclass) {
     /* Support weak references (needed for the keep_alive feature) */
     type->tp_weaklistoffset = offsetof(instance, weakrefs);
 
-    if (PyType_Ready(type) < 0)
+    if (PyType_Ready(type) < 0) {
         pybind11_fail("PyType_Ready failed in make_object_base_type():" + error_string());
+    }
 
     setattr((PyObject *) type, "__module__", str("pybind11_builtins"));
     PYBIND11_SET_OLDPY_QUALNAME(type, name_obj);
@@ -482,8 +501,9 @@ inline PyObject *make_object_base_type(PyTypeObject *metaclass) {
 /// dynamic_attr: Support for `d = instance.__dict__`.
 extern "C" inline PyObject *pybind11_get_dict(PyObject *self, void *) {
     PyObject *&dict = *_PyObject_GetDictPtr(self);
-    if (!dict)
+    if (!dict) {
         dict = PyDict_New();
+    }
     Py_XINCREF(dict);
     return dict;
 }
@@ -538,12 +558,14 @@ extern "C" inline int pybind11_getbuffer(PyObject *obj, Py_buffer *view, int fla
     type_info *tinfo = nullptr;
     for (auto type : reinterpret_borrow<tuple>(Py_TYPE(obj)->tp_mro)) {
         tinfo = get_type_info((PyTypeObject *) type.ptr());
-        if (tinfo && tinfo->get_buffer)
+        if (tinfo && tinfo->get_buffer) {
             break;
+        }
     }
     if (view == nullptr || !tinfo || !tinfo->get_buffer) {
-        if (view)
+        if (view) {
             view->obj = nullptr;
+        }
         PyErr_SetString(PyExc_BufferError, "pybind11_getbuffer(): Internal error");
         return -1;
     }
@@ -561,11 +583,13 @@ extern "C" inline int pybind11_getbuffer(PyObject *obj, Py_buffer *view, int fla
     view->buf = info->ptr;
     view->itemsize = info->itemsize;
     view->len = view->itemsize;
-    for (auto s : info->shape)
+    for (auto s : info->shape) {
         view->len *= s;
+    }
     view->readonly = static_cast<int>(info->readonly);
-    if ((flags & PyBUF_FORMAT) == PyBUF_FORMAT)
+    if ((flags & PyBUF_FORMAT) == PyBUF_FORMAT) {
         view->format = const_cast<char *>(info->format.c_str());
+    }
     if ((flags & PyBUF_STRIDES) == PyBUF_STRIDES) {
         view->ndim = (int) info->ndim;
         view->strides = info->strides.data();
@@ -608,10 +632,11 @@ inline PyObject* make_new_python_type(const type_record &rec) {
 
     object module_;
     if (rec.scope) {
-        if (hasattr(rec.scope, "__module__"))
+        if (hasattr(rec.scope, "__module__")) {
             module_ = rec.scope.attr("__module__");
-        else if (hasattr(rec.scope, "__name__"))
+        } else if (hasattr(rec.scope, "__name__")) {
             module_ = rec.scope.attr("__name__");
+        }
     }
 
     auto full_name = c_str(
@@ -642,8 +667,9 @@ inline PyObject* make_new_python_type(const type_record &rec) {
                                          : internals.default_metaclass;
 
     auto heap_type = (PyHeapTypeObject *) metaclass->tp_alloc(metaclass, 0);
-    if (!heap_type)
+    if (!heap_type) {
         pybind11_fail(std::string(rec.name) + ": Unable to create type object!");
+    }
 
     heap_type->ht_name = name.release().ptr();
 #ifdef PYBIND11_BUILTIN_QUALNAME
@@ -655,8 +681,9 @@ inline PyObject* make_new_python_type(const type_record &rec) {
     type->tp_doc = tp_doc;
     type->tp_base = type_incref((PyTypeObject *)base);
     type->tp_basicsize = static_cast<ssize_t>(sizeof(instance));
-    if (!bases.empty())
+    if (!bases.empty()) {
         type->tp_bases = bases.release().ptr();
+    }
 
     /* Don't inherit base __init__ */
     type->tp_init = pybind11_object_init;
@@ -674,31 +701,38 @@ inline PyObject* make_new_python_type(const type_record &rec) {
 #if PY_MAJOR_VERSION < 3
     type->tp_flags |= Py_TPFLAGS_CHECKTYPES;
 #endif
-    if (!rec.is_final)
+    if (!rec.is_final) {
         type->tp_flags |= Py_TPFLAGS_BASETYPE;
+    }
 
-    if (rec.dynamic_attr)
+    if (rec.dynamic_attr) {
         enable_dynamic_attributes(heap_type);
+    }
 
-    if (rec.buffer_protocol)
+    if (rec.buffer_protocol) {
         enable_buffer_protocol(heap_type);
+    }
 
-    if (rec.custom_type_setup_callback)
+    if (rec.custom_type_setup_callback) {
         rec.custom_type_setup_callback(heap_type);
+    }
 
-    if (PyType_Ready(type) < 0)
+    if (PyType_Ready(type) < 0) {
         pybind11_fail(std::string(rec.name) + ": PyType_Ready failed (" + error_string() + ")!");
+    }
 
     assert(!rec.dynamic_attr || PyType_HasFeature(type, Py_TPFLAGS_HAVE_GC));
 
     /* Register type with the parent scope */
-    if (rec.scope)
+    if (rec.scope) {
         setattr(rec.scope, rec.name, (PyObject *) type);
-    else
+    } else {
         Py_INCREF(type); // Keep it alive forever (reference leak)
+    }
 
-    if (module_) // Needed by pydoc
+    if (module_) { // Needed by pydoc
         setattr((PyObject *) type, "__module__", module_);
+    }
 
     PYBIND11_SET_OLDPY_QUALNAME(type, qualname);
 

include/pybind11/detail/init.h

@@ -33,7 +33,9 @@ private:
 PYBIND11_NAMESPACE_BEGIN(initimpl)
 
 inline void no_nullptr(void *ptr) {
-    if (!ptr) throw type_error("pybind11::init(): factory function returned nullptr");
+    if (!ptr) {
+        throw type_error("pybind11::init(): factory function returned nullptr");
+    }
 }
 
 // Implementing functions for all forms of py::init<...> and py::init(...)
@@ -136,9 +138,10 @@ void construct(value_and_holder &v_h, Holder<Class> holder, bool need_alias) {
     auto *ptr = holder_helper<Holder<Class>>::get(holder);
     no_nullptr(ptr);
     // If we need an alias, check that the held pointer is actually an alias instance
-    if (PYBIND11_SILENCE_MSVC_C4127(Class::has_alias) && need_alias && !is_alias<Class>(ptr))
+    if (PYBIND11_SILENCE_MSVC_C4127(Class::has_alias) && need_alias && !is_alias<Class>(ptr)) {
         throw type_error("pybind11::init(): construction failed: returned holder-wrapped instance "
                          "is not an alias instance");
+    }
 
     v_h.value_ptr() = ptr;
     v_h.type->init_instance(v_h.inst, &holder);
@@ -153,10 +156,11 @@ void construct(value_and_holder &v_h, Cpp<Class> &&result, bool need_alias) {
     PYBIND11_WORKAROUND_INCORRECT_MSVC_C4100(need_alias);
     static_assert(std::is_move_constructible<Cpp<Class>>::value,
         "pybind11::init() return-by-value factory function requires a movable class");
-    if (PYBIND11_SILENCE_MSVC_C4127(Class::has_alias) && need_alias)
+    if (PYBIND11_SILENCE_MSVC_C4127(Class::has_alias) && need_alias) {
         construct_alias_from_cpp<Class>(is_alias_constructible<Class>{}, v_h, std::move(result));
-    else
+    } else {
         v_h.value_ptr() = new Cpp<Class>(std::move(result));
+    }
 }
 
 // return-by-value version 2: returning a value of the alias type itself.  We move-construct an
@@ -183,12 +187,19 @@ struct constructor {
               enable_if_t<Class::has_alias &&
                           std::is_constructible<Cpp<Class>, Args...>::value, int> = 0>
     static void execute(Class &cl, const Extra&... extra) {
-        cl.def("__init__", [](value_and_holder &v_h, Args... args) {
-            if (Py_TYPE(v_h.inst) == v_h.type->type)
-                v_h.value_ptr() = construct_or_initialize<Cpp<Class>>(std::forward<Args>(args)...);
-            else
-                v_h.value_ptr() = construct_or_initialize<Alias<Class>>(std::forward<Args>(args)...);
-        }, is_new_style_constructor(), extra...);
+        cl.def(
+            "__init__",
+            [](value_and_holder &v_h, Args... args) {
+                if (Py_TYPE(v_h.inst) == v_h.type->type) {
+                    v_h.value_ptr()
+                        = construct_or_initialize<Cpp<Class>>(std::forward<Args>(args)...);
+                } else {
+                    v_h.value_ptr()
+                        = construct_or_initialize<Alias<Class>>(std::forward<Args>(args)...);
+                }
+            },
+            is_new_style_constructor(),
+            extra...);
     }
 
     template <typename Class, typename... Extra,

include/pybind11/detail/internals.h

@@ -398,8 +398,9 @@ inline void translate_local_exception(std::exception_ptr p) {
 /// Return a reference to the current `internals` data
 PYBIND11_NOINLINE internals &get_internals() {
     auto **&internals_pp = get_internals_pp();
-    if (internals_pp && *internals_pp)
+    if (internals_pp && *internals_pp) {
         return **internals_pp;
+    }
 
     // Ensure that the GIL is held since we will need to make Python calls.
     // Cannot use py::gil_scoped_acquire here since that constructor calls get_internals.
@@ -425,7 +426,9 @@ PYBIND11_NOINLINE internals &get_internals() {
         (*internals_pp)->registered_exception_translators.push_front(&translate_local_exception);
 #endif
     } else {
-        if (!internals_pp) internals_pp = new internals*();
+        if (!internals_pp) {
+            internals_pp = new internals *();
+        }
         auto *&internals_ptr = *internals_pp;
         internals_ptr = new internals();
 #if defined(WITH_THREAD)

include/pybind11/detail/type_caster_base.h

@@ -69,11 +69,13 @@ public:
 
     /// ... and destroyed after it returns
     ~loader_life_support() {
-        if (get_stack_top() != this)
+        if (get_stack_top() != this) {
             pybind11_fail("loader_life_support: internal error");
+        }
         set_stack_top(parent);
-        for (auto* item : keep_alive)
+        for (auto *item : keep_alive) {
             Py_DECREF(item);
+        }
     }
 
     /// This can only be used inside a pybind11-bound function, either by `argument_loader`
@@ -90,8 +92,9 @@ public:
                              "of temporary values");
         }
 
-        if (frame->keep_alive.insert(h.ptr()).second)
+        if (frame->keep_alive.insert(h.ptr()).second) {
             Py_INCREF(h.ptr());
+        }
     }
 };
 
@@ -103,14 +106,17 @@ inline std::pair<decltype(internals::registered_types_py)::iterator, bool> all_t
 // Populates a just-created cache entry.
 PYBIND11_NOINLINE void all_type_info_populate(PyTypeObject *t, std::vector<type_info *> &bases) {
     std::vector<PyTypeObject *> check;
-    for (handle parent : reinterpret_borrow<tuple>(t->tp_bases))
+    for (handle parent : reinterpret_borrow<tuple>(t->tp_bases)) {
         check.push_back((PyTypeObject *) parent.ptr());
+    }
 
     auto const &type_dict = get_internals().registered_types_py;
     for (size_t i = 0; i < check.size(); i++) {
         auto type = check[i];
         // Ignore Python2 old-style class super type:
-        if (!PyType_Check((PyObject *) type)) continue;
+        if (!PyType_Check((PyObject *) type)) {
+            continue;
+        }
 
         // Check `type` in the current set of registered python types:
         auto it = type_dict.find(type);
@@ -127,7 +133,9 @@ PYBIND11_NOINLINE void all_type_info_populate(PyTypeObject *t, std::vector<type_
                 for (auto *known : bases) {
                     if (known == tinfo) { found = true; break; }
                 }
-                if (!found) bases.push_back(tinfo);
+                if (!found) {
+                    bases.push_back(tinfo);
+                }
             }
         }
         else if (type->tp_bases) {
@@ -140,8 +148,9 @@ PYBIND11_NOINLINE void all_type_info_populate(PyTypeObject *t, std::vector<type_
                 check.pop_back();
                 i--;
             }
-            for (handle parent : reinterpret_borrow<tuple>(type->tp_bases))
+            for (handle parent : reinterpret_borrow<tuple>(type->tp_bases)) {
                 check.push_back((PyTypeObject *) parent.ptr());
+            }
         }
     }
 }
@@ -158,9 +167,10 @@ PYBIND11_NOINLINE void all_type_info_populate(PyTypeObject *t, std::vector<type_
  */
 inline const std::vector<detail::type_info *> &all_type_info(PyTypeObject *type) {
     auto ins = all_type_info_get_cache(type);
-    if (ins.second)
+    if (ins.second) {
         // New cache entry: populate it
         all_type_info_populate(type, ins.first->second);
+    }
 
     return ins.first->second;
 }
@@ -172,36 +182,43 @@ inline const std::vector<detail::type_info *> &all_type_info(PyTypeObject *type)
  */
 PYBIND11_NOINLINE detail::type_info* get_type_info(PyTypeObject *type) {
     auto &bases = all_type_info(type);
-    if (bases.empty())
+    if (bases.empty()) {
         return nullptr;
-    if (bases.size() > 1)
-        pybind11_fail("pybind11::detail::get_type_info: type has multiple pybind11-registered bases");
+    }
+    if (bases.size() > 1) {
+        pybind11_fail(
+            "pybind11::detail::get_type_info: type has multiple pybind11-registered bases");
+    }
     return bases.front();
 }
 
 inline detail::type_info *get_local_type_info(const std::type_index &tp) {
     auto &locals = get_local_internals().registered_types_cpp;
     auto it = locals.find(tp);
-    if (it != locals.end())
+    if (it != locals.end()) {
         return it->second;
+    }
     return nullptr;
 }
 
 inline detail::type_info *get_global_type_info(const std::type_index &tp) {
     auto &types = get_internals().registered_types_cpp;
     auto it = types.find(tp);
-    if (it != types.end())
+    if (it != types.end()) {
         return it->second;
+    }
     return nullptr;
 }
 
 /// Return the type info for a given C++ type; on lookup failure can either throw or return nullptr.
 PYBIND11_NOINLINE detail::type_info *get_type_info(const std::type_index &tp,
                                                           bool throw_if_missing = false) {
-    if (auto ltype = get_local_type_info(tp))
+    if (auto ltype = get_local_type_info(tp)) {
         return ltype;
-    if (auto gtype = get_global_type_info(tp))
+    }
+    if (auto gtype = get_global_type_info(tp)) {
         return gtype;
+    }
 
     if (throw_if_missing) {
         std::string tname = tp.name();
@@ -222,8 +239,9 @@ PYBIND11_NOINLINE handle find_registered_python_instance(void *src,
     auto it_instances = get_internals().registered_instances.equal_range(src);
     for (auto it_i = it_instances.first; it_i != it_instances.second; ++it_i) {
         for (auto instance_type : detail::all_type_info(Py_TYPE(it_i->second))) {
-            if (instance_type && same_type(*instance_type->cpptype, *tinfo->cpptype))
+            if (instance_type && same_type(*instance_type->cpptype, *tinfo->cpptype)) {
                 return handle((PyObject *) it_i->second).inc_ref();
+            }
         }
     }
     return handle();
@@ -263,12 +281,13 @@ struct value_and_holder {
     }
     // NOLINTNEXTLINE(readability-make-member-function-const)
     void set_holder_constructed(bool v = true) {
-        if (inst->simple_layout)
+        if (inst->simple_layout) {
             inst->simple_holder_constructed = v;
-        else if (v)
+        } else if (v) {
             inst->nonsimple.status[index] |= instance::status_holder_constructed;
-        else
+        } else {
             inst->nonsimple.status[index] &= (std::uint8_t) ~instance::status_holder_constructed;
+        }
     }
     bool instance_registered() const {
         return inst->simple_layout
@@ -277,12 +296,13 @@ struct value_and_holder {
     }
     // NOLINTNEXTLINE(readability-make-member-function-const)
     void set_instance_registered(bool v = true) {
-        if (inst->simple_layout)
+        if (inst->simple_layout) {
             inst->simple_instance_registered = v;
-        else if (v)
+        } else if (v) {
             inst->nonsimple.status[index] |= instance::status_instance_registered;
-        else
+        } else {
             inst->nonsimple.status[index] &= (std::uint8_t) ~instance::status_instance_registered;
+        }
     }
 };
 
@@ -317,8 +337,9 @@ public:
         bool operator==(const iterator &other) const { return curr.index == other.curr.index; }
         bool operator!=(const iterator &other) const { return curr.index != other.curr.index; }
         iterator &operator++() {
-            if (!inst->simple_layout)
+            if (!inst->simple_layout) {
                 curr.vh += 1 + (*types)[curr.index]->holder_size_in_ptrs;
+            }
             ++curr.index;
             curr.type = curr.index < types->size() ? (*types)[curr.index] : nullptr;
             return *this;
@@ -332,7 +353,9 @@ public:
 
     iterator find(const type_info *find_type) {
         auto it = begin(), endit = end();
-        while (it != endit && it->type != find_type) ++it;
+        while (it != endit && it->type != find_type) {
+            ++it;
+        }
         return it;
     }
 
@@ -351,16 +374,19 @@ public:
  */
 PYBIND11_NOINLINE value_and_holder instance::get_value_and_holder(const type_info *find_type /*= nullptr default in common.h*/, bool throw_if_missing /*= true in common.h*/) {
     // Optimize common case:
-    if (!find_type || Py_TYPE(this) == find_type->type)
+    if (!find_type || Py_TYPE(this) == find_type->type) {
         return value_and_holder(this, find_type, 0, 0);
+    }
 
     detail::values_and_holders vhs(this);
     auto it = vhs.find(find_type);
-    if (it != vhs.end())
+    if (it != vhs.end()) {
         return *it;
+    }
 
-    if (!throw_if_missing)
+    if (!throw_if_missing) {
         return value_and_holder();
+    }
 
 #if defined(NDEBUG)
     pybind11_fail("pybind11::detail::instance::get_value_and_holder: "
@@ -378,8 +404,10 @@ PYBIND11_NOINLINE void instance::allocate_layout() {
 
     const size_t n_types = tinfo.size();
 
-    if (n_types == 0)
-        pybind11_fail("instance allocation failed: new instance has no pybind11-registered base types");
+    if (n_types == 0) {
+        pybind11_fail(
+            "instance allocation failed: new instance has no pybind11-registered base types");
+    }
 
     simple_layout =
         n_types == 1 && tinfo.front()->holder_size_in_ptrs <= instance_simple_holder_in_ptrs();
@@ -410,7 +438,9 @@ PYBIND11_NOINLINE void instance::allocate_layout() {
         // just wrappers around malloc.
 #if PY_VERSION_HEX >= 0x03050000
         nonsimple.values_and_holders = (void **) PyMem_Calloc(space, sizeof(void *));
-        if (!nonsimple.values_and_holders) throw std::bad_alloc();
+        if (!nonsimple.values_and_holders) {
+            throw std::bad_alloc();
+        }
 #else
         nonsimple.values_and_holders = (void **) PyMem_New(void *, space);
         if (!nonsimple.values_and_holders) throw std::bad_alloc();
@@ -423,14 +453,16 @@ PYBIND11_NOINLINE void instance::allocate_layout() {
 
 // NOLINTNEXTLINE(readability-make-member-function-const)
 PYBIND11_NOINLINE void instance::deallocate_layout() {
-    if (!simple_layout)
+    if (!simple_layout) {
         PyMem_Free(nonsimple.values_and_holders);
+    }
 }
 
 PYBIND11_NOINLINE bool isinstance_generic(handle obj, const std::type_info &tp) {
     handle type = detail::get_type_handle(tp, false);
-    if (!type)
+    if (!type) {
         return false;
+    }
     return isinstance(obj, type);
 }
 
@@ -447,14 +479,16 @@ PYBIND11_NOINLINE std::string error_string() {
         errorString += handle(scope.type).attr("__name__").cast<std::string>();
         errorString += ": ";
     }
-    if (scope.value)
+    if (scope.value) {
         errorString += (std::string) str(scope.value);
+    }
 
     PyErr_NormalizeException(&scope.type, &scope.value, &scope.trace);
 
 #if PY_MAJOR_VERSION >= 3
-    if (scope.trace != nullptr)
+    if (scope.trace != nullptr) {
         PyException_SetTraceback(scope.value, scope.trace);
+    }
 #endif
 
 #if !defined(PYPY_VERSION)
@@ -462,8 +496,9 @@ PYBIND11_NOINLINE std::string error_string() {
         auto *trace = (PyTracebackObject *) scope.trace;
 
         /* Get the deepest trace possible */
-        while (trace->tb_next)
+        while (trace->tb_next) {
             trace = trace->tb_next;
+        }
 
         PyFrameObject *frame = trace->tb_frame;
         errorString += "\n\nAt:\n";
@@ -493,8 +528,9 @@ PYBIND11_NOINLINE handle get_object_handle(const void *ptr, const detail::type_i
     auto range = instances.equal_range(ptr);
     for (auto it = range.first; it != range.second; ++it) {
         for (const auto &vh : values_and_holders(it->second)) {
-            if (vh.type == type)
+            if (vh.type == type) {
                 return handle((PyObject *) it->second);
+            }
         }
     }
     return handle();
@@ -535,15 +571,18 @@ public:
                                          void *(*copy_constructor)(const void *),
                                          void *(*move_constructor)(const void *),
                                          const void *existing_holder = nullptr) {
-        if (!tinfo) // no type info: error will be set already
+        if (!tinfo) { // no type info: error will be set already
             return handle();
+        }
 
         void *src = const_cast<void *>(_src);
-        if (src == nullptr)
+        if (src == nullptr) {
             return none().release();
+        }
 
-        if (handle registered_inst = find_registered_python_instance(src, tinfo))
+        if (handle registered_inst = find_registered_python_instance(src, tinfo)) {
             return registered_inst;
+        }
 
         auto inst = reinterpret_steal<object>(make_new_instance(tinfo->type));
         auto wrapper = reinterpret_cast<instance *>(inst.ptr());
@@ -564,9 +603,9 @@ public:
                 break;
 
             case return_value_policy::copy:
-                if (copy_constructor)
+                if (copy_constructor) {
                     valueptr = copy_constructor(src);
-                else {
+                } else {
 #if defined(NDEBUG)
                     throw cast_error("return_value_policy = copy, but type is "
                                      "non-copyable! (compile in debug mode for details)");
@@ -581,11 +620,11 @@ public:
                 break;
 
             case return_value_policy::move:
-                if (move_constructor)
+                if (move_constructor) {
                     valueptr = move_constructor(src);
-                else if (copy_constructor)
+                } else if (copy_constructor) {
                     valueptr = copy_constructor(src);
-                else {
+                } else {
 #if defined(NDEBUG)
                     throw cast_error("return_value_policy = move, but type is neither "
                                      "movable nor copyable! "
@@ -650,8 +689,9 @@ public:
     }
     bool try_direct_conversions(handle src) {
         for (auto &converter : *typeinfo->direct_conversions) {
-            if (converter(src.ptr(), value))
+            if (converter(src.ptr(), value)) {
                 return true;
+            }
         }
         return false;
     }
@@ -659,8 +699,9 @@ public:
 
     PYBIND11_NOINLINE static void *local_load(PyObject *src, const type_info *ti) {
         auto caster = type_caster_generic(ti);
-        if (caster.load(src, false))
+        if (caster.load(src, false)) {
             return caster.value;
+        }
         return nullptr;
     }
 
@@ -669,14 +710,16 @@ public:
     PYBIND11_NOINLINE bool try_load_foreign_module_local(handle src) {
         constexpr auto *local_key = PYBIND11_MODULE_LOCAL_ID;
         const auto pytype = type::handle_of(src);
-        if (!hasattr(pytype, local_key))
+        if (!hasattr(pytype, local_key)) {
             return false;
+        }
 
         type_info *foreign_typeinfo = reinterpret_borrow<capsule>(getattr(pytype, local_key));
         // Only consider this foreign loader if actually foreign and is a loader of the correct cpp type
         if (foreign_typeinfo->module_local_load == &local_load
-            || (cpptype && !same_type(*cpptype, *foreign_typeinfo->cpptype)))
+            || (cpptype && !same_type(*cpptype, *foreign_typeinfo->cpptype))) {
             return false;
+        }
 
         if (auto result = foreign_typeinfo->module_local_load(src.ptr(), foreign_typeinfo)) {
             value = result;
@@ -690,8 +733,12 @@ public:
     // logic (without having to resort to virtual inheritance).
     template <typename ThisT>
     PYBIND11_NOINLINE bool load_impl(handle src, bool convert) {
-        if (!src) return false;
-        if (!typeinfo) return try_load_foreign_module_local(src);
+        if (!src) {
+            return false;
+        }
+        if (!typeinfo) {
+            return try_load_foreign_module_local(src);
+        }
 
         auto &this_ = static_cast<ThisT &>(*this);
         this_.check_holder_compat();
@@ -734,8 +781,9 @@ public:
             // Case 2c: C++ multiple inheritance is involved and we couldn't find an exact type match
             // in the registered bases, above, so try implicit casting (needed for proper C++ casting
             // when MI is involved).
-            if (this_.try_implicit_casts(src, convert))
+            if (this_.try_implicit_casts(src, convert)) {
                 return true;
+            }
         }
 
         // Perform an implicit conversion
@@ -747,8 +795,9 @@ public:
                     return true;
                 }
             }
-            if (this_.try_direct_conversions(src))
+            if (this_.try_direct_conversions(src)) {
                 return true;
+            }
         }
 
         // Failed to match local typeinfo. Try again with global.
@@ -767,7 +816,9 @@ public:
         // Custom converters didn't take None, now we convert None to nullptr.
         if (src.is_none()) {
            // Defer accepting None to other overloads (if we aren't in convert mode):
-           if (!convert) return false;
+           if (!convert) {
+               return false;
+           }
            value = nullptr;
            return true;
         }
@@ -907,8 +958,10 @@ public:
     explicit type_caster_base(const std::type_info &info) : type_caster_generic(info) { }
 
     static handle cast(const itype &src, return_value_policy policy, handle parent) {
-        if (policy == return_value_policy::automatic || policy == return_value_policy::automatic_reference)
+        if (policy == return_value_policy::automatic
+            || policy == return_value_policy::automatic_reference) {
             policy = return_value_policy::copy;
+        }
         return cast(&src, policy, parent);
     }
 
@@ -960,7 +1013,12 @@ public:
     // NOLINTNEXTLINE(google-explicit-constructor)
     operator itype*() { return (type *) value; }
     // NOLINTNEXTLINE(google-explicit-constructor)
-    operator itype&() { if (!value) throw reference_cast_error(); return *((itype *) value); }
+    operator itype&() {
+        if (!value) {
+            throw reference_cast_error();
+        }
+        return *((itype *) value);
+    }
 
 protected:
     using Constructor = void *(*)(const void *);

include/pybind11/detail/typeid.h

@@ -24,7 +24,9 @@ PYBIND11_NAMESPACE_BEGIN(detail)
 inline void erase_all(std::string &string, const std::string &search) {
     for (size_t pos = 0;;) {
         pos = string.find(search, pos);
-        if (pos == std::string::npos) break;
+        if (pos == std::string::npos) {
+            break;
+        }
         string.erase(pos, search.length());
     }
 }
@@ -34,8 +36,9 @@ PYBIND11_NOINLINE void clean_type_id(std::string &name) {
     int status = 0;
     std::unique_ptr<char, void (*)(void *)> res {
         abi::__cxa_demangle(name.c_str(), nullptr, nullptr, &status), std::free };
-    if (status == 0)
+    if (status == 0) {
         name = res.get();
+    }
 #else
     detail::erase_all(name, "class ");
     detail::erase_all(name, "struct ");

include/pybind11/eigen.h

@@ -145,8 +145,9 @@ template <typename Type_> struct EigenProps {
     // (preferring the latter if it will fit in either, i.e. for a fully dynamic matrix type).
     static EigenConformable<row_major> conformable(const array &a) {
         const auto dims = a.ndim();
-        if (dims < 1 || dims > 2)
+        if (dims < 1 || dims > 2) {
             return false;
+        }
 
         if (dims == 2) { // Matrix type: require exact match (or dynamic)
 
@@ -155,9 +156,10 @@ template <typename Type_> struct EigenProps {
                 np_cols = a.shape(1),
                 np_rstride = a.strides(0) / static_cast<ssize_t>(sizeof(Scalar)),
                 np_cstride = a.strides(1) / static_cast<ssize_t>(sizeof(Scalar));
-            if ((PYBIND11_SILENCE_MSVC_C4127(fixed_rows) && np_rows != rows) ||
-                (PYBIND11_SILENCE_MSVC_C4127(fixed_cols) && np_cols != cols))
+            if ((PYBIND11_SILENCE_MSVC_C4127(fixed_rows) && np_rows != rows)
+                || (PYBIND11_SILENCE_MSVC_C4127(fixed_cols) && np_cols != cols)) {
                 return false;
+            }
 
             return {np_rows, np_cols, np_rstride, np_cstride};
         }
@@ -168,8 +170,9 @@ template <typename Type_> struct EigenProps {
               stride = a.strides(0) / static_cast<ssize_t>(sizeof(Scalar));
 
         if (vector) { // Eigen type is a compile-time vector
-            if (PYBIND11_SILENCE_MSVC_C4127(fixed) && size != n)
+            if (PYBIND11_SILENCE_MSVC_C4127(fixed) && size != n) {
                 return false; // Vector size mismatch
+            }
             return {rows == 1 ? 1 : n, cols == 1 ? 1 : n, stride};
         }
         if (fixed) {
@@ -179,10 +182,14 @@ template <typename Type_> struct EigenProps {
         if (fixed_cols) {
             // Since this isn't a vector, cols must be != 1.  We allow this only if it exactly
             // equals the number of elements (rows is Dynamic, and so 1 row is allowed).
-            if (cols != n) return false;
+            if (cols != n) {
+                return false;
+            }
             return {1, n, stride};
         } // Otherwise it's either fully dynamic, or column dynamic; both become a column vector
-            if (PYBIND11_SILENCE_MSVC_C4127(fixed_rows) && rows != n) return false;
+        if (PYBIND11_SILENCE_MSVC_C4127(fixed_rows) && rows != n) {
+            return false;
+        }
             return {n, 1, stride};
     }
 
@@ -213,14 +220,18 @@ template <typename Type_> struct EigenProps {
 template <typename props> handle eigen_array_cast(typename props::Type const &src, handle base = handle(), bool writeable = true) {
     constexpr ssize_t elem_size = sizeof(typename props::Scalar);
     array a;
-    if (props::vector)
+    if (props::vector) {
         a = array({ src.size() }, { elem_size * src.innerStride() }, src.data(), base);
-    else
-        a = array({ src.rows(), src.cols() }, { elem_size * src.rowStride(), elem_size * src.colStride() },
-                  src.data(), base);
+    } else {
+        a = array({src.rows(), src.cols()},
+                  {elem_size * src.rowStride(), elem_size * src.colStride()},
+                  src.data(),
+                  base);
+    }
 
-    if (!writeable)
+    if (!writeable) {
         array_proxy(a.ptr())->flags &= ~detail::npy_api::NPY_ARRAY_WRITEABLE_;
+    }
 
     return a.release();
 }
@@ -255,28 +266,35 @@ struct type_caster<Type, enable_if_t<is_eigen_dense_plain<Type>::value>> {
 
     bool load(handle src, bool convert) {
         // If we're in no-convert mode, only load if given an array of the correct type
-        if (!convert && !isinstance<array_t<Scalar>>(src))
+        if (!convert && !isinstance<array_t<Scalar>>(src)) {
             return false;
+        }
 
         // Coerce into an array, but don't do type conversion yet; the copy below handles it.
         auto buf = array::ensure(src);
 
-        if (!buf)
+        if (!buf) {
             return false;
+        }
 
         auto dims = buf.ndim();
-        if (dims < 1 || dims > 2)
+        if (dims < 1 || dims > 2) {
             return false;
+        }
 
         auto fits = props::conformable(buf);
-        if (!fits)
+        if (!fits) {
             return false;
+        }
 
         // Allocate the new type, then build a numpy reference into it
         value = Type(fits.rows, fits.cols);
         auto ref = reinterpret_steal<array>(eigen_ref_array<props>(value));
-        if (dims == 1) ref = ref.squeeze();
-        else if (ref.ndim() == 1) buf = buf.squeeze();
+        if (dims == 1) {
+            ref = ref.squeeze();
+        } else if (ref.ndim() == 1) {
+            buf = buf.squeeze();
+        }
 
         int result = detail::npy_api::get().PyArray_CopyInto_(ref.ptr(), buf.ptr());
 
@@ -323,14 +341,18 @@ public:
     }
     // lvalue reference return; default (automatic) becomes copy
     static handle cast(Type &src, return_value_policy policy, handle parent) {
-        if (policy == return_value_policy::automatic || policy == return_value_policy::automatic_reference)
+        if (policy == return_value_policy::automatic
+            || policy == return_value_policy::automatic_reference) {
             policy = return_value_policy::copy;
+        }
         return cast_impl(&src, policy, parent);
     }
     // const lvalue reference return; default (automatic) becomes copy
     static handle cast(const Type &src, return_value_policy policy, handle parent) {
-        if (policy == return_value_policy::automatic || policy == return_value_policy::automatic_reference)
+        if (policy == return_value_policy::automatic
+            || policy == return_value_policy::automatic_reference) {
             policy = return_value_policy::copy;
+        }
         return cast(&src, policy, parent);
     }
     // non-const pointer return
@@ -439,11 +461,14 @@ public:
 
             if (aref && (!need_writeable || aref.writeable())) {
                 fits = props::conformable(aref);
-                if (!fits) return false; // Incompatible dimensions
-                if (!fits.template stride_compatible<props>())
+                if (!fits) {
+                    return false; // Incompatible dimensions
+                }
+                if (!fits.template stride_compatible<props>()) {
                     need_copy = true;
-                else
+                } else {
                     copy_or_ref = std::move(aref);
+                }
             }
             else {
                 need_copy = true;
@@ -454,13 +479,18 @@ public:
             // We need to copy: If we need a mutable reference, or we're not supposed to convert
             // (either because we're in the no-convert overload pass, or because we're explicitly
             // instructed not to copy (via `py::arg().noconvert()`) we have to fail loading.
-            if (!convert || need_writeable) return false;
+            if (!convert || need_writeable) {
+                return false;
+            }
 
             Array copy = Array::ensure(src);
-            if (!copy) return false;
+            if (!copy) {
+                return false;
+            }
             fits = props::conformable(copy);
-            if (!fits || !fits.template stride_compatible<props>())
+            if (!fits || !fits.template stride_compatible<props>()) {
                 return false;
+            }
             copy_or_ref = std::move(copy);
             loader_life_support::add_patient(copy_or_ref);
         }
@@ -550,8 +580,9 @@ struct type_caster<Type, enable_if_t<is_eigen_sparse<Type>::value>> {
     static constexpr bool rowMajor = Type::IsRowMajor;
 
     bool load(handle src, bool) {
-        if (!src)
+        if (!src) {
             return false;
+        }
 
         auto obj = reinterpret_borrow<object>(src);
         object sparse_module = module_::import("scipy.sparse");
@@ -572,8 +603,9 @@ struct type_caster<Type, enable_if_t<is_eigen_sparse<Type>::value>> {
         auto shape = pybind11::tuple((pybind11::object) obj.attr("shape"));
         auto nnz = obj.attr("nnz").cast<Index>();
 
-        if (!values || !innerIndices || !outerIndices)
+        if (!values || !innerIndices || !outerIndices) {
             return false;
+        }
 
         value = EigenMapSparseMatrix<Scalar,
                                      Type::Flags & (Eigen::RowMajor | Eigen::ColMajor),

include/pybind11/embed.h

@@ -77,12 +77,14 @@ struct embedded_module {
     using init_t = void (*)();
 #endif
     embedded_module(const char *name, init_t init) {
-        if (Py_IsInitialized() != 0)
+        if (Py_IsInitialized() != 0) {
             pybind11_fail("Can't add new modules after the interpreter has been initialized");
+        }
 
         auto result = PyImport_AppendInittab(name, init);
-        if (result == -1)
+        if (result == -1) {
             pybind11_fail("Insufficient memory to add a new module");
+        }
     }
 };
 
@@ -135,8 +137,9 @@ inline void set_interpreter_argv(int argc, const char *const *argv, bool add_pro
 
     const char *const empty_argv[]{"\0"};
     const char *const *safe_argv = special_case ? empty_argv : argv;
-    if (special_case)
+    if (special_case) {
         argc = 1;
+    }
 
     auto argv_size = static_cast<size_t>(argc);
 #if PY_MAJOR_VERSION >= 3
@@ -192,8 +195,9 @@ inline void initialize_interpreter(bool init_signal_handlers = true,
                                    int argc = 0,
                                    const char *const *argv = nullptr,
                                    bool add_program_dir_to_path = true) {
-    if (Py_IsInitialized() != 0)
+    if (Py_IsInitialized() != 0) {
         pybind11_fail("The interpreter is already running");
+    }
 
     Py_InitializeEx(init_signal_handlers ? 1 : 0);
 
@@ -244,8 +248,9 @@ inline void finalize_interpreter() {
     // during destruction), so we get the pointer-pointer here and check it after Py_Finalize().
     detail::internals **internals_ptr_ptr = detail::get_internals_pp();
     // It could also be stashed in builtins, so look there too:
-    if (builtins.contains(id) && isinstance<capsule>(builtins[id]))
+    if (builtins.contains(id) && isinstance<capsule>(builtins[id])) {
         internals_ptr_ptr = capsule(builtins[id]);
+    }
 
     Py_Finalize();
 
@@ -285,8 +290,9 @@ public:
     scoped_interpreter &operator=(scoped_interpreter &&) = delete;
 
     ~scoped_interpreter() {
-        if (is_valid)
+        if (is_valid) {
             finalize_interpreter();
+        }
     }
 
 private:

include/pybind11/eval.h

@@ -46,8 +46,9 @@ enum eval_mode {
 
 template <eval_mode mode = eval_expr>
 object eval(const str &expr, object global = globals(), object local = object()) {
-    if (!local)
+    if (!local) {
         local = global;
+    }
 
     detail::ensure_builtins_in_globals(global);
 
@@ -64,8 +65,9 @@ object eval(const str &expr, object global = globals(), object local = object())
     }
 
     PyObject *result = PyRun_String(buffer.c_str(), start, global.ptr(), local.ptr());
-    if (!result)
+    if (!result) {
         throw error_already_set();
+    }
     return reinterpret_steal<object>(result);
 }
 
@@ -102,8 +104,9 @@ object eval_file(str) {
 #else
 template <eval_mode mode = eval_statements>
 object eval_file(str fname, object global = globals(), object local = object()) {
-    if (!local)
+    if (!local) {
         local = global;
+    }
 
     detail::ensure_builtins_in_globals(global);
 
@@ -154,8 +157,9 @@ object eval_file(str fname, object global = globals(), object local = object())
                                     local.ptr(), closeFile);
 #endif
 
-    if (!result)
+    if (!result) {
         throw error_already_set();
+    }
     return reinterpret_steal<object>(result);
 }
 #endif

include/pybind11/functional.h

@@ -25,12 +25,15 @@ public:
     bool load(handle src, bool convert) {
         if (src.is_none()) {
             // Defer accepting None to other overloads (if we aren't in convert mode):
-            if (!convert) return false;
+            if (!convert) {
+                return false;
+            }
             return true;
         }
 
-        if (!isinstance<function>(src))
+        if (!isinstance<function>(src)) {
             return false;
+        }
 
         auto func = reinterpret_borrow<function>(src);
 
@@ -104,12 +107,14 @@ public:
 
     template <typename Func>
     static handle cast(Func &&f_, return_value_policy policy, handle /* parent */) {
-        if (!f_)
+        if (!f_) {
             return none().inc_ref();
+        }
 
         auto result = f_.template target<function_type>();
-        if (result)
+        if (result) {
             return cpp_function(*result, policy).release();
+        }
         return cpp_function(std::forward<Func>(f_), policy).release();
     }
 

include/pybind11/gil.h

@@ -99,8 +99,9 @@ public:
                     pybind11_fail("scoped_acquire::dec_ref(): internal error!");
             #endif
             PyThreadState_Clear(tstate);
-            if (active)
+            if (active) {
                 PyThreadState_DeleteCurrent();
+            }
             PYBIND11_TLS_DELETE_VALUE(detail::get_internals().tstate);
             release = false;
         }
@@ -117,8 +118,9 @@ public:
 
     PYBIND11_NOINLINE ~gil_scoped_acquire() {
         dec_ref();
-        if (release)
-           PyEval_SaveThread();
+        if (release) {
+            PyEval_SaveThread();
+        }
     }
 private:
     PyThreadState *tstate = nullptr;
@@ -150,11 +152,13 @@ public:
     }
 
     ~gil_scoped_release() {
-        if (!tstate)
+        if (!tstate) {
             return;
+        }
         // `PyEval_RestoreThread()` should not be called if runtime is finalizing
-        if (active)
+        if (active) {
             PyEval_RestoreThread(tstate);
+        }
         if (disassoc) {
             auto key = detail::get_internals().tstate;
             PYBIND11_TLS_REPLACE_VALUE(key, tstate);

include/pybind11/iostream.h

@@ -71,23 +71,26 @@ private:
             return static_cast<unsigned char>(c) <= 0xEF;
         };
         // If the last character is ASCII, there are no incomplete code points
-        if (is_ascii(*rpptr))
+        if (is_ascii(*rpptr)) {
             return 0;
+        }
         // Otherwise, work back from the end of the buffer and find the first
         // UTF-8 leading byte
         const auto rpend   = rbase - rpptr >= 3 ? rpptr + 3 : rbase;
         const auto leading = std::find_if(rpptr, rpend, is_leading);
-        if (leading == rbase)
+        if (leading == rbase) {
             return 0;
+        }
         const auto dist    = static_cast<size_t>(leading - rpptr);
         size_t remainder   = 0;
 
-        if (dist == 0)
+        if (dist == 0) {
             remainder = 1; // 1-byte code point is impossible
-        else if (dist == 1)
+        } else if (dist == 1) {
             remainder = is_leading_2b(*leading) ? 0 : dist + 1;
-        else if (dist == 2)
+        } else if (dist == 2) {
             remainder = is_leading_3b(*leading) ? 0 : dist + 1;
+        }
         // else if (dist >= 3), at least 4 bytes before encountering an UTF-8
         // leading byte, either no remainder or invalid UTF-8.
         // Invalid UTF-8 will cause an exception later when converting
@@ -110,8 +113,9 @@ private:
             }
 
             // Copy the remainder at the end of the buffer to the beginning:
-            if (remainder > 0)
+            if (remainder > 0) {
                 std::memmove(pbase(), pptr() - remainder, remainder);
+            }
             setp(pbase(), epptr());
             pbump(static_cast<int>(remainder));
         }
@@ -223,10 +227,12 @@ public:
         : do_stdout_(do_stdout), do_stderr_(do_stderr) {}
 
     void enter() {
-        if (do_stdout_)
+        if (do_stdout_) {
             redirect_stdout.reset(new scoped_ostream_redirect());
-        if (do_stderr_)
+        }
+        if (do_stderr_) {
             redirect_stderr.reset(new scoped_estream_redirect());
+        }
     }
 
     void exit() {

include/pybind11/numpy.h

@@ -87,10 +87,12 @@ struct numpy_internals {
 
     numpy_type_info *get_type_info(const std::type_info& tinfo, bool throw_if_missing = true) {
         auto it = registered_dtypes.find(std::type_index(tinfo));
-        if (it != registered_dtypes.end())
+        if (it != registered_dtypes.end()) {
             return &(it->second);
-        if (throw_if_missing)
+        }
+        if (throw_if_missing) {
             pybind11_fail(std::string("NumPy type info missing for ") + tinfo.name());
+        }
         return nullptr;
     }
 
@@ -105,8 +107,9 @@ PYBIND11_NOINLINE void load_numpy_internals(numpy_internals* &ptr) {
 
 inline numpy_internals& get_numpy_internals() {
     static numpy_internals* ptr = nullptr;
-    if (!ptr)
+    if (!ptr) {
         load_numpy_internals(ptr);
+    }
     return *ptr;
 }
 
@@ -235,8 +238,9 @@ private:
         npy_api api;
 #define DECL_NPY_API(Func) api.Func##_ = (decltype(api.Func##_)) api_ptr[API_##Func];
         DECL_NPY_API(PyArray_GetNDArrayCFeatureVersion);
-        if (api.PyArray_GetNDArrayCFeatureVersion_() < 0x7)
+        if (api.PyArray_GetNDArrayCFeatureVersion_() < 0x7) {
             pybind11_fail("pybind11 numpy support requires numpy >= 1.7.0");
+        }
         DECL_NPY_API(PyArray_Type);
         DECL_NPY_API(PyVoidArrType_Type);
         DECL_NPY_API(PyArrayDescr_Type);
@@ -491,8 +495,9 @@ public:
     /// This is essentially the same as calling numpy.dtype(args) in Python.
     static dtype from_args(object args) {
         PyObject *ptr = nullptr;
-        if ((detail::npy_api::get().PyArray_DescrConverter_(args.ptr(), &ptr) == 0) || !ptr)
+        if ((detail::npy_api::get().PyArray_DescrConverter_(args.ptr(), &ptr) == 0) || !ptr) {
             throw error_already_set();
+        }
         return reinterpret_steal<dtype>(ptr);
     }
 
@@ -536,8 +541,9 @@ private:
     dtype strip_padding(ssize_t itemsize) {
         // Recursively strip all void fields with empty names that are generated for
         // padding fields (as of NumPy v1.11).
-        if (!has_fields())
+        if (!has_fields()) {
             return *this;
+        }
 
         struct field_descr { PYBIND11_STR_TYPE name; object format; pybind11::int_ offset; };
         std::vector<field_descr> field_descriptors;
@@ -547,8 +553,9 @@ private:
             auto name = spec[0].cast<pybind11::str>();
             auto format = spec[1].cast<tuple>()[0].cast<dtype>();
             auto offset = spec[1].cast<tuple>()[1].cast<pybind11::int_>();
-            if ((len(name) == 0u) && format.kind() == 'V')
+            if ((len(name) == 0u) && format.kind() == 'V') {
                 continue;
+            }
             field_descriptors.push_back({(PYBIND11_STR_TYPE) name, format.strip_padding(format.itemsize()), offset});
         }
 
@@ -586,22 +593,25 @@ public:
     array(const pybind11::dtype &dt, ShapeContainer shape, StridesContainer strides,
           const void *ptr = nullptr, handle base = handle()) {
 
-        if (strides->empty())
+        if (strides->empty()) {
             *strides = detail::c_strides(*shape, dt.itemsize());
+        }
 
         auto ndim = shape->size();
-        if (ndim != strides->size())
+        if (ndim != strides->size()) {
             pybind11_fail("NumPy: shape ndim doesn't match strides ndim");
+        }
         auto descr = dt;
 
         int flags = 0;
         if (base && ptr) {
-            if (isinstance<array>(base))
+            if (isinstance<array>(base)) {
                 /* Copy flags from base (except ownership bit) */
                 flags = reinterpret_borrow<array>(base).flags() & ~detail::npy_api::NPY_ARRAY_OWNDATA_;
-            else
+            } else {
                 /* Writable by default, easy to downgrade later on if needed */
                 flags = detail::npy_api::NPY_ARRAY_WRITEABLE_;
+            }
         }
 
         auto &api = detail::npy_api::get();
@@ -611,8 +621,9 @@ public:
             reinterpret_cast<Py_intptr_t*>(shape->data()),
             reinterpret_cast<Py_intptr_t*>(strides->data()),
             const_cast<void *>(ptr), flags, nullptr));
-        if (!tmp)
+        if (!tmp) {
             throw error_already_set();
+        }
         if (ptr) {
             if (base) {
                 api.PyArray_SetBaseObject_(tmp.ptr(), base.inc_ref().ptr());
@@ -681,8 +692,9 @@ public:
 
     /// Dimension along a given axis
     ssize_t shape(ssize_t dim) const {
-        if (dim >= ndim())
+        if (dim >= ndim()) {
             fail_dim_check(dim, "invalid axis");
+        }
         return shape()[dim];
     }
 
@@ -693,8 +705,9 @@ public:
 
     /// Stride along a given axis
     ssize_t strides(ssize_t dim) const {
-        if (dim >= ndim())
+        if (dim >= ndim()) {
             fail_dim_check(dim, "invalid axis");
+        }
         return strides()[dim];
     }
 
@@ -730,8 +743,9 @@ public:
     /// Byte offset from beginning of the array to a given index (full or partial).
     /// May throw if the index would lead to out of bounds access.
     template<typename... Ix> ssize_t offset_at(Ix... index) const {
-        if ((ssize_t) sizeof...(index) > ndim())
+        if ((ssize_t) sizeof...(index) > ndim()) {
             fail_dim_check(sizeof...(index), "too many indices for an array");
+        }
         return byte_offset(ssize_t(index)...);
     }
 
@@ -750,9 +764,11 @@ public:
      * and the caller must take care not to access invalid dimensions or dimension indices.
      */
     template <typename T, ssize_t Dims = -1> detail::unchecked_mutable_reference<T, Dims> mutable_unchecked() & {
-        if (PYBIND11_SILENCE_MSVC_C4127(Dims >= 0) && ndim() != Dims)
-            throw std::domain_error("array has incorrect number of dimensions: " + std::to_string(ndim()) +
-                    "; expected " + std::to_string(Dims));
+        if (PYBIND11_SILENCE_MSVC_C4127(Dims >= 0) && ndim() != Dims) {
+            throw std::domain_error("array has incorrect number of dimensions: "
+                                    + std::to_string(ndim()) + "; expected "
+                                    + std::to_string(Dims));
+        }
         return detail::unchecked_mutable_reference<T, Dims>(mutable_data(), shape(), strides(), ndim());
     }
 
@@ -764,9 +780,11 @@ public:
      * invalid dimensions or dimension indices.
      */
     template <typename T, ssize_t Dims = -1> detail::unchecked_reference<T, Dims> unchecked() const & {
-        if (PYBIND11_SILENCE_MSVC_C4127(Dims >= 0) && ndim() != Dims)
-            throw std::domain_error("array has incorrect number of dimensions: " + std::to_string(ndim()) +
-                    "; expected " + std::to_string(Dims));
+        if (PYBIND11_SILENCE_MSVC_C4127(Dims >= 0) && ndim() != Dims) {
+            throw std::domain_error("array has incorrect number of dimensions: "
+                                    + std::to_string(ndim()) + "; expected "
+                                    + std::to_string(Dims));
+        }
         return detail::unchecked_reference<T, Dims>(data(), shape(), strides(), ndim());
     }
 
@@ -789,7 +807,9 @@ public:
         auto new_array = reinterpret_steal<object>(
             detail::npy_api::get().PyArray_Resize_(m_ptr, &d, int(refcheck), -1)
         );
-        if (!new_array) throw error_already_set();
+        if (!new_array) {
+            throw error_already_set();
+        }
         if (isinstance<array>(new_array)) { *this = std::move(new_array); }
     }
 
@@ -824,8 +844,9 @@ public:
     /// In case of an error, nullptr is returned and the Python error is cleared.
     static array ensure(handle h, int ExtraFlags = 0) {
         auto result = reinterpret_steal<array>(raw_array(h.ptr(), ExtraFlags));
-        if (!result)
+        if (!result) {
             PyErr_Clear();
+        }
         return result;
     }
 
@@ -843,8 +864,9 @@ protected:
     }
 
     void check_writeable() const {
-        if (!writeable())
+        if (!writeable()) {
             throw std::domain_error("array is not writeable");
+        }
     }
 
     template<typename... Ix> void check_dimensions(Ix... index) const {
@@ -890,13 +912,19 @@ public:
 
     PYBIND11_DEPRECATED("Use array_t<T>::ensure() instead")
     array_t(handle h, bool is_borrowed) : array(raw_array_t(h.ptr()), stolen_t{}) {
-        if (!m_ptr) PyErr_Clear();
-        if (!is_borrowed) Py_XDECREF(h.ptr());
+        if (!m_ptr) {
+            PyErr_Clear();
+        }
+        if (!is_borrowed) {
+            Py_XDECREF(h.ptr());
+        }
     }
 
     // NOLINTNEXTLINE(google-explicit-constructor)
     array_t(const object &o) : array(raw_array_t(o.ptr()), stolen_t{}) {
-        if (!m_ptr) throw error_already_set();
+        if (!m_ptr) {
+            throw error_already_set();
+        }
     }
 
     explicit array_t(const buffer_info& info, handle base = handle()) : array(info, base) { }
@@ -933,15 +961,17 @@ public:
 
     // Reference to element at a given index
     template<typename... Ix> const T& at(Ix... index) const {
-        if ((ssize_t) sizeof...(index) != ndim())
+        if ((ssize_t) sizeof...(index) != ndim()) {
             fail_dim_check(sizeof...(index), "index dimension mismatch");
+        }
         return *(static_cast<const T*>(array::data()) + byte_offset(ssize_t(index)...) / itemsize());
     }
 
     // Mutable reference to element at a given index
     template<typename... Ix> T& mutable_at(Ix... index) {
-        if ((ssize_t) sizeof...(index) != ndim())
+        if ((ssize_t) sizeof...(index) != ndim()) {
             fail_dim_check(sizeof...(index), "index dimension mismatch");
+        }
         return *(static_cast<T*>(array::mutable_data()) + byte_offset(ssize_t(index)...) / itemsize());
     }
 
@@ -970,8 +1000,9 @@ public:
     /// it).  In case of an error, nullptr is returned and the Python error is cleared.
     static array_t ensure(handle h) {
         auto result = reinterpret_steal<array_t>(raw_array_t(h.ptr()));
-        if (!result)
+        if (!result) {
             PyErr_Clear();
+        }
         return result;
     }
 
@@ -1032,8 +1063,9 @@ struct pyobject_caster<array_t<T, ExtraFlags>> {
     using type = array_t<T, ExtraFlags>;
 
     bool load(handle src, bool convert) {
-        if (!convert && !type::check_(src))
+        if (!convert && !type::check_(src)) {
             return false;
+        }
         value = type::ensure(src);
         return static_cast<bool>(value);
     }
@@ -1098,8 +1130,9 @@ public:
     static constexpr int value = values[detail::is_fmt_numeric<T>::index];
 
     static pybind11::dtype dtype() {
-        if (auto ptr = npy_api::get().PyArray_DescrFromType_(value))
+        if (auto ptr = npy_api::get().PyArray_DescrFromType_(value)) {
             return reinterpret_steal<pybind11::dtype>(ptr);
+        }
         pybind11_fail("Unsupported buffer format!");
     }
 };
@@ -1147,8 +1180,9 @@ PYBIND11_NOINLINE void register_structured_dtype(
     bool (*direct_converter)(PyObject *, void *&)) {
 
     auto& numpy_internals = get_numpy_internals();
-    if (numpy_internals.get_type_info(tinfo, false))
+    if (numpy_internals.get_type_info(tinfo, false)) {
         pybind11_fail("NumPy: dtype is already registered");
+    }
 
     // Use ordered fields because order matters as of NumPy 1.14:
     // https://docs.scipy.org/doc/numpy/release.html#multiple-field-indexing-assignment-of-structured-arrays
@@ -1158,9 +1192,10 @@ PYBIND11_NOINLINE void register_structured_dtype(
 
     list names, formats, offsets;
     for (auto& field : ordered_fields) {
-        if (!field.descr)
-            pybind11_fail(std::string("NumPy: unsupported field dtype: `") +
-                            field.name + "` @ " + tinfo.name());
+        if (!field.descr) {
+            pybind11_fail(std::string("NumPy: unsupported field dtype: `") + field.name + "` @ "
+                          + tinfo.name());
+        }
         names.append(PYBIND11_STR_TYPE(field.name));
         formats.append(field.descr);
         offsets.append(pybind11::int_(field.offset));
@@ -1186,21 +1221,24 @@ PYBIND11_NOINLINE void register_structured_dtype(
     // isn't guaranteed to work due to https://github.com/numpy/numpy/issues/9049
     oss << "^T{";
     for (auto& field : ordered_fields) {
-        if (field.offset > offset)
+        if (field.offset > offset) {
             oss << (field.offset - offset) << 'x';
+        }
         oss << field.format << ':' << field.name << ':';
         offset = field.offset + field.size;
     }
-    if (itemsize > offset)
+    if (itemsize > offset) {
         oss << (itemsize - offset) << 'x';
+    }
     oss << '}';
     auto format_str = oss.str();
 
     // Sanity check: verify that NumPy properly parses our buffer format string
     auto& api = npy_api::get();
     auto arr =  array(buffer_info(nullptr, itemsize, format_str, 1));
-    if (!api.PyArray_EquivTypes_(dtype_ptr, arr.dtype().ptr()))
+    if (!api.PyArray_EquivTypes_(dtype_ptr, arr.dtype().ptr())) {
         pybind11_fail("NumPy: invalid buffer descriptor!");
+    }
 
     auto tindex = std::type_index(tinfo);
     numpy_internals.registered_dtypes[tindex] = { dtype_ptr, format_str };
@@ -1234,8 +1272,9 @@ private:
 
     static bool direct_converter(PyObject *obj, void*& value) {
         auto& api = npy_api::get();
-        if (!PyObject_TypeCheck(obj, api.PyVoidArrType_Type_))
+        if (!PyObject_TypeCheck(obj, api.PyVoidArrType_Type_)) {
             return false;
+        }
         if (auto descr = reinterpret_steal<object>(api.PyArray_DescrFromScalar_(obj))) {
             if (api.PyArray_EquivTypes_(dtype_ptr(), descr.ptr())) {
                 value = ((PyVoidScalarObject_Proxy *) obj)->obval;
@@ -1363,12 +1402,14 @@ public:
           m_common_iterator() {
 
         // Manual copy to avoid conversion warning if using std::copy
-        for (size_t i = 0; i < shape.size(); ++i)
+        for (size_t i = 0; i < shape.size(); ++i) {
             m_shape[i] = shape[i];
+        }
 
         container_type strides(shape.size());
-        for (size_t i = 0; i < N; ++i)
+        for (size_t i = 0; i < N; ++i) {
             init_common_iterator(buffers[i], shape, m_common_iterator[i], strides);
+        }
     }
 
     multi_array_iterator& operator++() {
@@ -1401,10 +1442,11 @@ private:
         auto strides_iter = strides.rbegin();
 
         while (buffer_shape_iter != buffer.shape.rend()) {
-            if (*shape_iter == *buffer_shape_iter)
+            if (*shape_iter == *buffer_shape_iter) {
                 *strides_iter = *buffer_strides_iter;
-            else
+            } else {
                 *strides_iter = 0;
+            }
 
             ++buffer_shape_iter;
             ++buffer_strides_iter;
@@ -1417,8 +1459,9 @@ private:
     }
 
     void increment_common_iterator(size_t dim) {
-        for (auto &iter : m_common_iterator)
+        for (auto &iter : m_common_iterator) {
             iter.increment(dim);
+        }
     }
 
     container_type m_shape;
@@ -1451,26 +1494,30 @@ broadcast_trivial broadcast(const std::array<buffer_info, N> &buffers, ssize_t &
             auto &dim_size_out = *res_iter;
 
             // Each input dimension can either be 1 or `n`, but `n` values must match across buffers
-            if (dim_size_out == 1)
+            if (dim_size_out == 1) {
                 dim_size_out = dim_size_in;
-            else if (dim_size_in != 1 && dim_size_in != dim_size_out)
+            } else if (dim_size_in != 1 && dim_size_in != dim_size_out) {
                 pybind11_fail("pybind11::vectorize: incompatible size/dimension of inputs!");
+            }
         }
     }
 
     bool trivial_broadcast_c = true;
     bool trivial_broadcast_f = true;
     for (size_t i = 0; i < N && (trivial_broadcast_c || trivial_broadcast_f); ++i) {
-        if (buffers[i].size == 1)
+        if (buffers[i].size == 1) {
             continue;
+        }
 
         // Require the same number of dimensions:
-        if (buffers[i].ndim != ndim)
+        if (buffers[i].ndim != ndim) {
             return broadcast_trivial::non_trivial;
+        }
 
         // Require all dimensions be full-size:
-        if (!std::equal(buffers[i].shape.cbegin(), buffers[i].shape.cend(), shape.cbegin()))
+        if (!std::equal(buffers[i].shape.cbegin(), buffers[i].shape.cend(), shape.cbegin())) {
             return broadcast_trivial::non_trivial;
+        }
 
         // Check for C contiguity (but only if previous inputs were also C contiguous)
         if (trivial_broadcast_c) {
@@ -1478,10 +1525,11 @@ broadcast_trivial broadcast(const std::array<buffer_info, N> &buffers, ssize_t &
             auto end = buffers[i].shape.crend();
             for (auto shape_iter = buffers[i].shape.crbegin(), stride_iter = buffers[i].strides.crbegin();
                     trivial_broadcast_c && shape_iter != end; ++shape_iter, ++stride_iter) {
-                if (expect_stride == *stride_iter)
+                if (expect_stride == *stride_iter) {
                     expect_stride *= *shape_iter;
-                else
+                } else {
                     trivial_broadcast_c = false;
+                }
             }
         }
 
@@ -1491,10 +1539,11 @@ broadcast_trivial broadcast(const std::array<buffer_info, N> &buffers, ssize_t &
             auto end = buffers[i].shape.cend();
             for (auto shape_iter = buffers[i].shape.cbegin(), stride_iter = buffers[i].strides.cbegin();
                     trivial_broadcast_f && shape_iter != end; ++shape_iter, ++stride_iter) {
-                if (expect_stride == *stride_iter)
+                if (expect_stride == *stride_iter) {
                     expect_stride *= *shape_iter;
-                else
+                } else {
                     trivial_broadcast_f = false;
+                }
             }
         }
     }
@@ -1527,8 +1576,9 @@ struct vectorize_returned_array {
     using Type = array_t<Return>;
 
     static Type create(broadcast_trivial trivial, const std::vector<ssize_t> &shape) {
-        if (trivial == broadcast_trivial::f_trivial)
+        if (trivial == broadcast_trivial::f_trivial) {
             return array_t<Return, array::f_style>(shape);
+        }
         return array_t<Return>(shape);
     }
 
@@ -1644,14 +1694,17 @@ private:
 
         auto result = returned_array::create(trivial, shape);
 
-        if (size == 0) return std::move(result);
+        if (size == 0) {
+            return std::move(result);
+        }
 
         /* Call the function */
         auto mutable_data = returned_array::mutable_data(result);
-        if (trivial == broadcast_trivial::non_trivial)
+        if (trivial == broadcast_trivial::non_trivial) {
             apply_broadcast(buffers, params, mutable_data, size, shape, i_seq, vi_seq, bi_seq);
-        else
+        } else {
             apply_trivial(buffers, params, mutable_data, size, i_seq, vi_seq, bi_seq);
+        }
 
         return std::move(result);
     }
@@ -1675,7 +1728,9 @@ private:
 
         for (size_t i = 0; i < size; ++i) {
             returned_array::call(out, i, f, *reinterpret_cast<param_n_t<Index> *>(params[Index])...);
-            for (auto &x : vecparams) x.first += x.second;
+            for (auto &x : vecparams) {
+                x.first += x.second;
+            }
         }
     }
 

include/pybind11/pytypes.h

@@ -242,7 +242,11 @@ class object : public handle {
 public:
     object() = default;
     PYBIND11_DEPRECATED("Use reinterpret_borrow<object>() or reinterpret_steal<object>()")
-    object(handle h, bool is_borrowed) : handle(h) { if (is_borrowed) inc_ref(); }
+    object(handle h, bool is_borrowed) : handle(h) {
+        if (is_borrowed) {
+            inc_ref();
+        }
+    }
     /// Copy constructor; always increases the reference count
     object(const object &o) : handle(o) { inc_ref(); }
     /// Move constructor; steals the object from ``other`` and preserves its reference count
@@ -458,8 +462,9 @@ template <> inline bool isinstance<object>(handle obj) { return obj.ptr() != nul
 /// Return true if ``obj`` is an instance of the ``type``.
 inline bool isinstance(handle obj, handle type) {
     const auto result = PyObject_IsInstance(obj.ptr(), type.ptr());
-    if (result == -1)
+    if (result == -1) {
         throw error_already_set();
+    }
     return result != 0;
 }
 
@@ -529,12 +534,13 @@ PYBIND11_NAMESPACE_BEGIN(detail)
 inline handle get_function(handle value) {
     if (value) {
 #if PY_MAJOR_VERSION >= 3
-        if (PyInstanceMethod_Check(value.ptr()))
+        if (PyInstanceMethod_Check(value.ptr())) {
             value = PyInstanceMethod_GET_FUNCTION(value.ptr());
-        else
+        } else
 #endif
-        if (PyMethod_Check(value.ptr()))
+            if (PyMethod_Check(value.ptr())) {
             value = PyMethod_GET_FUNCTION(value.ptr());
+        }
     }
     return value;
 }
@@ -1076,14 +1082,18 @@ public:
     template <typename SzType, detail::enable_if_t<std::is_integral<SzType>::value, int> = 0>
     str(const char *c, const SzType &n)
         : object(PyUnicode_FromStringAndSize(c, ssize_t_cast(n)), stolen_t{}) {
-        if (!m_ptr) pybind11_fail("Could not allocate string object!");
+        if (!m_ptr) {
+            pybind11_fail("Could not allocate string object!");
+        }
     }
 
     // 'explicit' is explicitly omitted from the following constructors to allow implicit conversion to py::str from C++ string-like objects
     // NOLINTNEXTLINE(google-explicit-constructor)
     str(const char *c = "")
         : object(PyUnicode_FromString(c), stolen_t{}) {
-        if (!m_ptr) pybind11_fail("Could not allocate string object!");
+        if (!m_ptr) {
+            pybind11_fail("Could not allocate string object!");
+        }
     }
 
     // NOLINTNEXTLINE(google-explicit-constructor)
@@ -1109,20 +1119,26 @@ public:
         Return a string representation of the object. This is analogous to
         the ``str()`` function in Python.
     \endrst */
-    explicit str(handle h) : object(raw_str(h.ptr()), stolen_t{}) { if (!m_ptr) throw error_already_set(); }
+    explicit str(handle h) : object(raw_str(h.ptr()), stolen_t{}) {
+        if (!m_ptr) {
+            throw error_already_set();
+        }
+    }
 
     // NOLINTNEXTLINE(google-explicit-constructor)
     operator std::string() const {
         object temp = *this;
         if (PyUnicode_Check(m_ptr)) {
             temp = reinterpret_steal<object>(PyUnicode_AsUTF8String(m_ptr));
-            if (!temp)
+            if (!temp) {
                 throw error_already_set();
+            }
         }
         char *buffer = nullptr;
         ssize_t length = 0;
-        if (PYBIND11_BYTES_AS_STRING_AND_SIZE(temp.ptr(), &buffer, &length))
+        if (PYBIND11_BYTES_AS_STRING_AND_SIZE(temp.ptr(), &buffer, &length)) {
             pybind11_fail("Unable to extract string contents! (invalid type)");
+        }
         return std::string(buffer, (size_t) length);
     }
 
@@ -1162,13 +1178,17 @@ public:
     // NOLINTNEXTLINE(google-explicit-constructor)
     bytes(const char *c = "")
         : object(PYBIND11_BYTES_FROM_STRING(c), stolen_t{}) {
-        if (!m_ptr) pybind11_fail("Could not allocate bytes object!");
+        if (!m_ptr) {
+            pybind11_fail("Could not allocate bytes object!");
+        }
     }
 
     template <typename SzType, detail::enable_if_t<std::is_integral<SzType>::value, int> = 0>
     bytes(const char *c, const SzType &n)
         : object(PYBIND11_BYTES_FROM_STRING_AND_SIZE(c, ssize_t_cast(n)), stolen_t{}) {
-        if (!m_ptr) pybind11_fail("Could not allocate bytes object!");
+        if (!m_ptr) {
+            pybind11_fail("Could not allocate bytes object!");
+        }
     }
 
     // Allow implicit conversion:
@@ -1181,8 +1201,9 @@ public:
     operator std::string() const {
         char *buffer = nullptr;
         ssize_t length = 0;
-        if (PYBIND11_BYTES_AS_STRING_AND_SIZE(m_ptr, &buffer, &length))
+        if (PYBIND11_BYTES_AS_STRING_AND_SIZE(m_ptr, &buffer, &length)) {
             pybind11_fail("Unable to extract bytes contents!");
+        }
         return std::string(buffer, (size_t) length);
     }
 
@@ -1199,8 +1220,9 @@ public:
     operator std::string_view() const {
         char *buffer = nullptr;
         ssize_t length = 0;
-        if (PYBIND11_BYTES_AS_STRING_AND_SIZE(m_ptr, &buffer, &length))
+        if (PYBIND11_BYTES_AS_STRING_AND_SIZE(m_ptr, &buffer, &length)) {
             pybind11_fail("Unable to extract bytes contents!");
+        }
         return {buffer, static_cast<size_t>(length)};
     }
 #endif
@@ -1214,27 +1236,32 @@ inline bytes::bytes(const pybind11::str &s) {
     object temp = s;
     if (PyUnicode_Check(s.ptr())) {
         temp = reinterpret_steal<object>(PyUnicode_AsUTF8String(s.ptr()));
-        if (!temp)
+        if (!temp) {
             pybind11_fail("Unable to extract string contents! (encoding issue)");
+        }
     }
     char *buffer = nullptr;
     ssize_t length = 0;
-    if (PYBIND11_BYTES_AS_STRING_AND_SIZE(temp.ptr(), &buffer, &length))
+    if (PYBIND11_BYTES_AS_STRING_AND_SIZE(temp.ptr(), &buffer, &length)) {
         pybind11_fail("Unable to extract string contents! (invalid type)");
+    }
     auto obj = reinterpret_steal<object>(PYBIND11_BYTES_FROM_STRING_AND_SIZE(buffer, length));
-    if (!obj)
+    if (!obj) {
         pybind11_fail("Could not allocate bytes object!");
+    }
     m_ptr = obj.release().ptr();
 }
 
 inline str::str(const bytes& b) {
     char *buffer = nullptr;
     ssize_t length = 0;
-    if (PYBIND11_BYTES_AS_STRING_AND_SIZE(b.ptr(), &buffer, &length))
+    if (PYBIND11_BYTES_AS_STRING_AND_SIZE(b.ptr(), &buffer, &length)) {
         pybind11_fail("Unable to extract bytes contents!");
+    }
     auto obj = reinterpret_steal<object>(PyUnicode_FromStringAndSize(buffer, length));
-    if (!obj)
+    if (!obj) {
         pybind11_fail("Could not allocate string object!");
+    }
     m_ptr = obj.release().ptr();
 }
 
@@ -1247,7 +1274,9 @@ public:
     template <typename SzType, detail::enable_if_t<std::is_integral<SzType>::value, int> = 0>
     bytearray(const char *c, const SzType &n)
         : object(PyByteArray_FromStringAndSize(c, ssize_t_cast(n)), stolen_t{}) {
-        if (!m_ptr) pybind11_fail("Could not allocate bytearray object!");
+        if (!m_ptr) {
+            pybind11_fail("Could not allocate bytearray object!");
+        }
     }
 
     bytearray()
@@ -1295,7 +1324,9 @@ private:
     /// Return the truth value of an object -- always returns a new reference
     static PyObject *raw_bool(PyObject *op) {
         const auto value = PyObject_IsTrue(op);
-        if (value == -1) return nullptr;
+        if (value == -1) {
+            return nullptr;
+        }
         return handle(value != 0 ? Py_True : Py_False).inc_ref().ptr();
     }
 };
@@ -1330,17 +1361,21 @@ public:
     // NOLINTNEXTLINE(google-explicit-constructor)
     int_(T value) {
         if (PYBIND11_SILENCE_MSVC_C4127(sizeof(T) <= sizeof(long))) {
-            if (std::is_signed<T>::value)
+            if (std::is_signed<T>::value) {
                 m_ptr = PyLong_FromLong((long) value);
-            else
+            } else {
                 m_ptr = PyLong_FromUnsignedLong((unsigned long) value);
+            }
         } else {
-            if (std::is_signed<T>::value)
+            if (std::is_signed<T>::value) {
                 m_ptr = PyLong_FromLongLong((long long) value);
-            else
+            } else {
                 m_ptr = PyLong_FromUnsignedLongLong((unsigned long long) value);
+            }
+        }
+        if (!m_ptr) {
+            pybind11_fail("Could not allocate int object!");
         }
-        if (!m_ptr) pybind11_fail("Could not allocate int object!");
     }
 
     template <typename T,
@@ -1361,11 +1396,15 @@ public:
     // Allow implicit conversion from float/double:
     // NOLINTNEXTLINE(google-explicit-constructor)
     float_(float value) : object(PyFloat_FromDouble((double) value), stolen_t{}) {
-        if (!m_ptr) pybind11_fail("Could not allocate float object!");
+        if (!m_ptr) {
+            pybind11_fail("Could not allocate float object!");
+        }
     }
     // NOLINTNEXTLINE(google-explicit-constructor)
     float_(double value = .0) : object(PyFloat_FromDouble((double) value), stolen_t{}) {
-        if (!m_ptr) pybind11_fail("Could not allocate float object!");
+        if (!m_ptr) {
+            pybind11_fail("Could not allocate float object!");
+        }
     }
     // NOLINTNEXTLINE(google-explicit-constructor)
     operator float() const { return (float) PyFloat_AsDouble(m_ptr); }
@@ -1378,7 +1417,9 @@ public:
     PYBIND11_OBJECT_CVT_DEFAULT(weakref, object, PyWeakref_Check, raw_weakref)
     explicit weakref(handle obj, handle callback = {})
         : object(PyWeakref_NewRef(obj.ptr(), callback.ptr()), stolen_t{}) {
-        if (!m_ptr) pybind11_fail("Could not allocate weak reference!");
+        if (!m_ptr) {
+            pybind11_fail("Could not allocate weak reference!");
+        }
     }
 
 private:
@@ -1392,8 +1433,9 @@ public:
     PYBIND11_OBJECT_DEFAULT(slice, object, PySlice_Check)
     slice(handle start, handle stop, handle step) {
         m_ptr = PySlice_New(start.ptr(), stop.ptr(), step.ptr());
-        if (!m_ptr)
+        if (!m_ptr) {
             pybind11_fail("Could not allocate slice object!");
+        }
     }
 
 #ifdef PYBIND11_HAS_OPTIONAL
@@ -1434,15 +1476,17 @@ public:
 
     explicit capsule(const void *value, const char *name = nullptr, void (*destructor)(PyObject *) = nullptr)
         : object(PyCapsule_New(const_cast<void *>(value), name, destructor), stolen_t{}) {
-        if (!m_ptr)
+        if (!m_ptr) {
             pybind11_fail("Could not allocate capsule object!");
+        }
     }
 
     PYBIND11_DEPRECATED("Please pass a destructor that takes a void pointer as input")
     capsule(const void *value, void (*destruct)(PyObject *))
         : object(PyCapsule_New(const_cast<void*>(value), nullptr, destruct), stolen_t{}) {
-        if (!m_ptr)
+        if (!m_ptr) {
             pybind11_fail("Could not allocate capsule object!");
+        }
     }
 
     capsule(const void *value, void (*destructor)(void *)) {
@@ -1452,11 +1496,13 @@ public:
             destructor(ptr);
         });
 
-        if (!m_ptr)
+        if (!m_ptr) {
             pybind11_fail("Could not allocate capsule object!");
+        }
 
-        if (PyCapsule_SetContext(m_ptr, (void *) destructor) != 0)
+        if (PyCapsule_SetContext(m_ptr, (void *) destructor) != 0) {
             pybind11_fail("Could not set capsule context!");
+        }
     }
 
     explicit capsule(void (*destructor)()) {
@@ -1465,8 +1511,9 @@ public:
             destructor();
         });
 
-        if (!m_ptr)
+        if (!m_ptr) {
             pybind11_fail("Could not allocate capsule object!");
+        }
     }
 
     // NOLINTNEXTLINE(google-explicit-constructor)
@@ -1504,7 +1551,9 @@ public:
               detail::enable_if_t<std::is_integral<SzType>::value, int> = 0>
     // Some compilers generate link errors when using `const SzType &` here:
     explicit tuple(SzType size = 0) : object(PyTuple_New(ssize_t_cast(size)), stolen_t{}) {
-        if (!m_ptr) pybind11_fail("Could not allocate tuple object!");
+        if (!m_ptr) {
+            pybind11_fail("Could not allocate tuple object!");
+        }
     }
     size_t size() const { return (size_t) PyTuple_Size(m_ptr); }
     bool empty() const { return size() == 0; }
@@ -1527,7 +1576,9 @@ class dict : public object {
 public:
     PYBIND11_OBJECT_CVT(dict, object, PyDict_Check, raw_dict)
     dict() : object(PyDict_New(), stolen_t{}) {
-        if (!m_ptr) pybind11_fail("Could not allocate dict object!");
+        if (!m_ptr) {
+            pybind11_fail("Could not allocate dict object!");
+        }
     }
     template <typename... Args,
               typename = detail::enable_if_t<args_are_all_keyword_or_ds<Args...>()>,
@@ -1547,8 +1598,9 @@ public:
 private:
     /// Call the `dict` Python type -- always returns a new reference
     static PyObject *raw_dict(PyObject *op) {
-        if (PyDict_Check(op))
+        if (PyDict_Check(op)) {
             return handle(op).inc_ref().ptr();
+        }
         return PyObject_CallFunctionObjArgs((PyObject *) &PyDict_Type, op, nullptr);
     }
 };
@@ -1558,8 +1610,9 @@ public:
     PYBIND11_OBJECT_DEFAULT(sequence, object, PySequence_Check)
     size_t size() const {
         ssize_t result = PySequence_Size(m_ptr);
-        if (result == -1)
+        if (result == -1) {
             throw error_already_set();
+        }
         return (size_t) result;
     }
     bool empty() const { return size() == 0; }
@@ -1576,7 +1629,9 @@ public:
               detail::enable_if_t<std::is_integral<SzType>::value, int> = 0>
     // Some compilers generate link errors when using `const SzType &` here:
     explicit list(SzType size = 0) : object(PyList_New(ssize_t_cast(size)), stolen_t{}) {
-        if (!m_ptr) pybind11_fail("Could not allocate list object!");
+        if (!m_ptr) {
+            pybind11_fail("Could not allocate list object!");
+        }
     }
     size_t size() const { return (size_t) PyList_Size(m_ptr); }
     bool empty() const { return size() == 0; }
@@ -1603,7 +1658,9 @@ class set : public object {
 public:
     PYBIND11_OBJECT_CVT(set, object, PySet_Check, PySet_New)
     set() : object(PySet_New(nullptr), stolen_t{}) {
-        if (!m_ptr) pybind11_fail("Could not allocate set object!");
+        if (!m_ptr) {
+            pybind11_fail("Could not allocate set object!");
+        }
     }
     size_t size() const { return (size_t) PySet_Size(m_ptr); }
     bool empty() const { return size() == 0; }
@@ -1621,8 +1678,9 @@ public:
     PYBIND11_OBJECT_DEFAULT(function, object, PyCallable_Check)
     handle cpp_function() const {
         handle fun = detail::get_function(m_ptr);
-        if (fun && PyCFunction_Check(fun.ptr()))
+        if (fun && PyCFunction_Check(fun.ptr())) {
             return fun;
+        }
         return handle();
     }
     bool is_cpp_function() const { return (bool) cpp_function(); }
@@ -1639,7 +1697,9 @@ public:
 
     buffer_info request(bool writable = false) const {
         int flags = PyBUF_STRIDES | PyBUF_FORMAT;
-        if (writable) flags |= PyBUF_WRITABLE;
+        if (writable) {
+            flags |= PyBUF_WRITABLE;
+        }
         auto *view = new Py_buffer();
         if (PyObject_GetBuffer(m_ptr, view, flags) != 0) {
             delete view;
@@ -1663,14 +1723,16 @@ public:
         use ``memoryview(const object& obj)`` instead of this constructor.
      \endrst */
     explicit memoryview(const buffer_info& info) {
-        if (!info.view())
+        if (!info.view()) {
             pybind11_fail("Prohibited to create memoryview without Py_buffer");
+        }
         // Note: PyMemoryView_FromBuffer never increments obj reference.
         m_ptr = (info.view()->obj) ?
             PyMemoryView_FromObject(info.view()->obj) :
             PyMemoryView_FromBuffer(info.view());
-        if (!m_ptr)
+        if (!m_ptr) {
             pybind11_fail("Unable to create memoryview from buffer descriptor");
+        }
     }
 
     /** \rst
@@ -1744,8 +1806,9 @@ public:
         PyObject* ptr = PyMemoryView_FromMemory(
             reinterpret_cast<char*>(mem), size,
             (readonly) ? PyBUF_READ : PyBUF_WRITE);
-        if (!ptr)
+        if (!ptr) {
             pybind11_fail("Could not allocate memoryview object!");
+        }
         return memoryview(object(ptr, stolen_t{}));
     }
 
@@ -1768,11 +1831,13 @@ inline memoryview memoryview::from_buffer(
     detail::any_container<ssize_t> shape,
     detail::any_container<ssize_t> strides, bool readonly) {
     size_t ndim = shape->size();
-    if (ndim != strides->size())
+    if (ndim != strides->size()) {
         pybind11_fail("memoryview: shape length doesn't match strides length");
+    }
     ssize_t size = ndim != 0u ? 1 : 0;
-    for (size_t i = 0; i < ndim; ++i)
+    for (size_t i = 0; i < ndim; ++i) {
         size *= (*shape)[i];
+    }
     Py_buffer view;
     view.buf = ptr;
     view.obj = nullptr;
@@ -1786,8 +1851,9 @@ inline memoryview memoryview::from_buffer(
     view.suboffsets = nullptr;
     view.internal = nullptr;
     PyObject* obj = PyMemoryView_FromBuffer(&view);
-    if (!obj)
+    if (!obj) {
         throw error_already_set();
+    }
     return memoryview(object(obj, stolen_t{}));
 }
 /// @endcond
@@ -1799,8 +1865,9 @@ inline memoryview memoryview::from_buffer(
 /// Get the length of a Python object.
 inline size_t len(handle h) {
     ssize_t result = PyObject_Length(h.ptr());
-    if (result < 0)
+    if (result < 0) {
         throw error_already_set();
+    }
     return (size_t) result;
 }
 
@@ -1823,7 +1890,9 @@ inline size_t len_hint(handle h) {
 
 inline str repr(handle h) {
     PyObject *str_value = PyObject_Repr(h.ptr());
-    if (!str_value) throw error_already_set();
+    if (!str_value) {
+        throw error_already_set();
+    }
 #if PY_MAJOR_VERSION < 3
     PyObject *unicode = PyUnicode_FromEncodedObject(str_value, "utf-8", nullptr);
     Py_XDECREF(str_value); str_value = unicode;
@@ -1873,8 +1942,9 @@ handle object_api<D>::get_type() const { return type::handle_of(derived()); }
 template <typename D>
 bool object_api<D>::rich_compare(object_api const &other, int value) const {
     int rv = PyObject_RichCompareBool(derived().ptr(), other.derived().ptr(), value);
-    if (rv == -1)
+    if (rv == -1) {
         throw error_already_set();
+    }
     return rv == 1;
 }