style: clang-tidy: modernize-use-auto

.clang-tidy

@@ -7,6 +7,7 @@ modernize-use-override,
 readability-container-size-empty,
 modernize-use-using,
 modernize-use-equals-default,
+modernize-use-auto,
 '
 
 HeaderFilterRegex: 'pybind11/.*h'

include/pybind11/cast.h

@@ -432,7 +432,7 @@ PYBIND11_NOINLINE inline std::string error_string() {
 
 #if !defined(PYPY_VERSION)
     if (scope.trace) {
-        PyTracebackObject *trace = (PyTracebackObject *) scope.trace;
+        auto *trace = (PyTracebackObject *) scope.trace;
 
         /* Get the deepest trace possible */
         while (trace->tb_next)
@@ -1244,7 +1244,7 @@ template <typename StringType, bool IsView = false> struct string_caster {
             load_src.ptr(), UTF_N == 8 ? "utf-8" : UTF_N == 16 ? "utf-16" : "utf-32", nullptr));
         if (!utfNbytes) { PyErr_Clear(); return false; }
 
-        const CharT *buffer = reinterpret_cast<const CharT *>(PYBIND11_BYTES_AS_STRING(utfNbytes.ptr()));
+        const auto *buffer = reinterpret_cast<const CharT *>(PYBIND11_BYTES_AS_STRING(utfNbytes.ptr()));
         size_t length = (size_t) PYBIND11_BYTES_SIZE(utfNbytes.ptr()) / sizeof(CharT);
         if (UTF_N > 8) { buffer++; length--; } // Skip BOM for UTF-16/32
         value = StringType(buffer, length);
@@ -1258,7 +1258,7 @@ template <typename StringType, bool IsView = false> struct string_caster {
 
     static handle cast(const StringType &src, return_value_policy /* policy */, handle /* parent */) {
         const char *buffer = reinterpret_cast<const char *>(src.data());
-        ssize_t nbytes = ssize_t(src.size() * sizeof(CharT));
+        auto nbytes = ssize_t(src.size() * sizeof(CharT));
         handle s = decode_utfN(buffer, nbytes);
         if (!s) throw error_already_set();
         return s;
@@ -1364,7 +1364,7 @@ public:
         // errors.  We also allow want to allow unicode characters U+0080 through U+00FF, as those
         // can fit into a single char value.
         if (StringCaster::UTF_N == 8 && str_len > 1 && str_len <= 4) {
-            unsigned char v0 = static_cast<unsigned char>(value[0]);
+            auto v0 = static_cast<unsigned char>(value[0]);
             size_t char0_bytes = !(v0 & 0x80) ? 1 : // low bits only: 0-127
                 (v0 & 0xE0) == 0xC0 ? 2 : // 0b110xxxxx - start of 2-byte sequence
                 (v0 & 0xF0) == 0xE0 ? 3 : // 0b1110xxxx - start of 3-byte sequence

include/pybind11/numpy.h

@@ -1296,7 +1296,7 @@ public:
         m_strides.back() = static_cast<value_type>(strides.back());
         for (size_type i = m_strides.size() - 1; i != 0; --i) {
             size_type j = i - 1;
-            value_type s = static_cast<value_type>(shape[i]);
+            auto s = static_cast<value_type>(shape[i]);
             m_strides[j] = strides[j] + m_strides[i] - strides[i] * s;
         }
     }
@@ -1539,7 +1539,7 @@ private:
         ssize_t nd = 0;
         std::vector<ssize_t> shape(0);
         auto trivial = broadcast(buffers, nd, shape);
-        size_t ndim = (size_t) nd;
+        auto ndim = (size_t) nd;
 
         size_t size = std::accumulate(shape.begin(), shape.end(), (size_t) 1, std::multiplies<size_t>());
 

include/pybind11/pybind11.h

@@ -165,7 +165,7 @@ protected:
             /* Get a pointer to the capture object */
             auto data = (sizeof(capture) <= sizeof(call.func.data)
                          ? &call.func.data : call.func.data[0]);
-            capture *cap = const_cast<capture *>(reinterpret_cast<const capture *>(data));
+            auto *cap = const_cast<capture *>(reinterpret_cast<const capture *>(data));
 
             /* Override policy for rvalues -- usually to enforce rvp::move on an rvalue */
             return_value_policy policy = return_value_policy_override<Return>::policy(call.func.policy);
@@ -420,7 +420,7 @@ protected:
         }
 
         /* Install docstring */
-        PyCFunctionObject *func = (PyCFunctionObject *) m_ptr;
+        auto *func = (PyCFunctionObject *) m_ptr;
         if (func->m_ml->ml_doc)
             std::free(const_cast<char *>(func->m_ml->ml_doc));
         func->m_ml->ml_doc = strdup(signatures.c_str());
@@ -465,7 +465,7 @@ protected:
                               *it = overloads;
 
         /* Need to know how many arguments + keyword arguments there are to pick the right overload */
-        const size_t n_args_in = (size_t) PyTuple_GET_SIZE(args_in);
+        const auto n_args_in = (size_t) PyTuple_GET_SIZE(args_in);
 
         handle parent = n_args_in > 0 ? PyTuple_GET_ITEM(args_in, 0) : nullptr,
                result = PYBIND11_TRY_NEXT_OVERLOAD;
@@ -860,7 +860,7 @@ public:
     explicit module(const char *name, const char *doc = nullptr) {
         if (!options::show_user_defined_docstrings()) doc = nullptr;
 #if PY_MAJOR_VERSION >= 3
-        PyModuleDef *def = new PyModuleDef();
+        auto *def = new PyModuleDef();
         std::memset(def, 0, sizeof(PyModuleDef));
         def->m_name = name;
         def->m_doc = doc;
@@ -1020,7 +1020,7 @@ protected:
     void install_buffer_funcs(
             buffer_info *(*get_buffer)(PyObject *, void *),
             void *get_buffer_data) {
-        PyHeapTypeObject *type = (PyHeapTypeObject*) m_ptr;
+        auto *type = (PyHeapTypeObject*) m_ptr;
         auto tinfo = detail::get_type_info(&type->ht_type);
 
         if (!type->ht_type.tp_as_buffer)
@@ -1242,7 +1242,7 @@ public:
 
     template <typename Func> class_& def_buffer(Func &&func) {
         struct capture { Func func; };
-        capture *ptr = new capture { std::forward<Func>(func) };
+        auto *ptr = new capture { std::forward<Func>(func) };
         install_buffer_funcs([](PyObject *obj, void *ptr) -> buffer_info* {
             detail::make_caster<type> caster;
             if (!caster.load(obj, false))

include/pybind11/pytypes.h

@@ -1351,7 +1351,7 @@ public:
     buffer_info request(bool writable = false) const {
         int flags = PyBUF_STRIDES | PyBUF_FORMAT;
         if (writable) flags |= PyBUF_WRITABLE;
-        Py_buffer *view = new Py_buffer();
+        auto *view = new Py_buffer();
         if (PyObject_GetBuffer(m_ptr, view, flags) != 0) {
             delete view;
             throw error_already_set();

include/pybind11/stl_bind.h

@@ -223,7 +223,7 @@ void vector_modifiers(enable_if_t<is_copy_constructible<typename Vector::value_t
             if (!slice.compute(v.size(), &start, &stop, &step, &slicelength))
                 throw error_already_set();
 
-            Vector *seq = new Vector();
+            auto *seq = new Vector();
             seq->reserve((size_t) slicelength);
 
             for (size_t i=0; i<slicelength; ++i) {

tests/test_numpy_array.cpp

@@ -212,7 +212,7 @@ TEST_SUBMODULE(numpy_array, sm) {
         .def(py::init<>())
         .def("numpy_view", [](py::object &obj) {
             py::print("ArrayClass::numpy_view()");
-            ArrayClass &a = obj.cast<ArrayClass&>();
+            auto &a = obj.cast<ArrayClass&>();
             return py::array_t<int>({2}, {4}, a.data, obj);
         }
     );
@@ -362,7 +362,7 @@ TEST_SUBMODULE(numpy_array, sm) {
     // test_array_resize
     // reshape array to 2D without changing size
     sm.def("array_reshape2", [](py::array_t<double> a) {
-        const ssize_t dim_sz = (ssize_t)std::sqrt(a.size());
+        const auto dim_sz = (ssize_t)std::sqrt(a.size());
         if (dim_sz * dim_sz != a.size())
             throw std::domain_error("array_reshape2: input array total size is not a squared integer");
         a.resize({dim_sz, dim_sz});

tests/test_opaque_types.cpp

@@ -60,7 +60,7 @@ TEST_SUBMODULE(opaque_types, m) {
     m.def("get_null_str_value", [](char *ptr) { return reinterpret_cast<std::intptr_t>(ptr); });
 
     m.def("return_unique_ptr", []() -> std::unique_ptr<StringList> {
-        StringList *result = new StringList();
+        auto *result = new StringList();
         result->push_back("some value");
         return std::unique_ptr<StringList>(result);
     });

tests/test_sequences_and_iterators.cpp

@@ -200,7 +200,7 @@ TEST_SUBMODULE(sequences_and_iterators, m) {
             size_t start, stop, step, slicelength;
             if (!slice.compute(s.size(), &start, &stop, &step, &slicelength))
                 throw py::error_already_set();
-            Sequence *seq = new Sequence(slicelength);
+            auto *seq = new Sequence(slicelength);
             for (size_t i = 0; i < slicelength; ++i) {
                 (*seq)[i] = s[start]; start += step;
             }