Merge branch 'master' into stable

pyproject.toml

@@ -15,6 +15,12 @@ ignore = [
     "noxfile.py",
 ]
 
+[tool.isort]
+# Needs the compiled .so modules and env.py from tests
+known_first_party = "env,pybind11_cross_module_tests,pybind11_tests,"
+# For black compatibility
+profile = "black"
+
 [tool.mypy]
 files = "pybind11"
 python_version = "2.7"

setup.py

@@ -4,6 +4,7 @@
 # Setup script for PyPI; use CMakeFile.txt to build extension modules
 
 import contextlib
+import io
 import os
 import re
 import shutil
@@ -11,7 +12,6 @@ import string
 import subprocess
 import sys
 import tempfile
-import io
 
 import setuptools.command.sdist
 

tests/CMakeLists.txt

@@ -10,10 +10,10 @@ cmake_minimum_required(VERSION 3.4)
 # The `cmake_minimum_required(VERSION 3.4...3.18)` syntax does not work with
 # some versions of VS that have a patched CMake 3.11. This forces us to emulate
 # the behavior using the following workaround:
-if(${CMAKE_VERSION} VERSION_LESS 3.18)
+if(${CMAKE_VERSION} VERSION_LESS 3.21)
   cmake_policy(VERSION ${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION})
 else()
-  cmake_policy(VERSION 3.18)
+  cmake_policy(VERSION 3.21)
 endif()
 
 # Only needed for CMake < 3.5 support
@@ -104,6 +104,7 @@ set(PYBIND11_TEST_FILES
     test_constants_and_functions.cpp
     test_copy_move.cpp
     test_custom_type_casters.cpp
+    test_custom_type_setup.cpp
     test_docstring_options.cpp
     test_eigen.cpp
     test_enum.cpp
@@ -129,6 +130,7 @@ set(PYBIND11_TEST_FILES
     test_stl.cpp
     test_stl_binders.cpp
     test_tagbased_polymorphic.cpp
+    test_thread.cpp
     test_union.cpp
     test_virtual_functions.cpp)
 
@@ -169,6 +171,14 @@ set(PYBIND11_CROSS_MODULE_TESTS test_exceptions.py test_local_bindings.py test_s
 
 set(PYBIND11_CROSS_MODULE_GIL_TESTS test_gil_scoped.py)
 
+set(PYBIND11_EIGEN_REPO
+    "https://gitlab.com/libeigen/eigen.git"
+    CACHE STRING "Eigen repository to use for tests")
+# This hash is for 3.3.8, using a hash for security reasons
+set(PYBIND11_EIGEN_VERSION
+    "dc252fbf00079ccab57948a164b1421703fe4361"
+    CACHE STRING "Eigen version to use for tests")
+
 # Check if Eigen is available; if not, remove from PYBIND11_TEST_FILES (but
 # keep it in PYBIND11_PYTEST_FILES, so that we get the "eigen is not installed"
 # skip message).
@@ -182,13 +192,11 @@ if(PYBIND11_TEST_FILES_EIGEN_I GREATER -1)
       message(FATAL_ERROR "CMake 3.11+ required when using DOWNLOAD_EIGEN")
     endif()
 
-    set(EIGEN3_VERSION_STRING "3.3.8")
-
     include(FetchContent)
     FetchContent_Declare(
       eigen
-      GIT_REPOSITORY https://gitlab.com/libeigen/eigen.git
-      GIT_TAG ${EIGEN3_VERSION_STRING})
+      GIT_REPOSITORY "${PYBIND11_EIGEN_REPO}"
+      GIT_TAG "${PYBIND11_EIGEN_VERSION}")
 
     FetchContent_GetProperties(eigen)
     if(NOT eigen_POPULATED)

tests/extra_setuptools/test_setuphelper.py

 # -*- coding: utf-8 -*-
 import os
-import sys
 import subprocess
+import sys
 from textwrap import dedent
 
 import pytest

tests/local_bindings.h

@@ -6,7 +6,7 @@
 /// Simple class used to test py::local:
 template <int> class LocalBase {
 public:
-    LocalBase(int i) : i(i) { }
+    explicit LocalBase(int i) : i(i) { }
     int i = -1;
 };
 
@@ -35,6 +35,25 @@ using NonLocalVec2 = std::vector<NonLocal2>;
 using NonLocalMap = std::unordered_map<std::string, NonLocalType>;
 using NonLocalMap2 = std::unordered_map<std::string, uint8_t>;
 
+
+// Exception that will be caught via the module local translator.
+class LocalException : public std::exception {
+public:
+    explicit LocalException(const char * m) : message{m} {}
+    const char * what() const noexcept override {return message.c_str();}
+private:
+    std::string message = "";
+};
+
+// Exception that will be registered with register_local_exception_translator
+class LocalSimpleException : public std::exception {
+public:
+    explicit LocalSimpleException(const char * m) : message{m} {}
+    const char * what() const noexcept override {return message.c_str();}
+private:
+    std::string message = "";
+};
+
 PYBIND11_MAKE_OPAQUE(LocalVec);
 PYBIND11_MAKE_OPAQUE(LocalVec2);
 PYBIND11_MAKE_OPAQUE(LocalMap);
@@ -56,11 +75,11 @@ py::class_<T> bind_local(Args && ...args) {
 namespace pets {
 class Pet {
 public:
-    Pet(std::string name) : name_(std::move(name)) {}
+    explicit Pet(std::string name) : name_(std::move(name)) {}
     std::string name_;
     const std::string &name() const { return name_; }
 };
 } // namespace pets
 
-struct MixGL { int i; MixGL(int i) : i{i} {} };
-struct MixGL2 { int i; MixGL2(int i) : i{i} {} };
+struct MixGL { int i; explicit MixGL(int i) : i{i} {} };
+struct MixGL2 { int i; explicit MixGL2(int i) : i{i} {} };

tests/object.h

@@ -65,7 +65,7 @@ public:
     ref() : m_ptr(nullptr) { print_default_created(this); track_default_created((ref_tag*) this); }
 
     /// Construct a reference from a pointer
-    ref(T *ptr) : m_ptr(ptr) {
+    explicit ref(T *ptr) : m_ptr(ptr) {
         if (m_ptr) ((Object *) m_ptr)->incRef();
 
         print_created(this, "from pointer", m_ptr); track_created((ref_tag*) this, "from pointer");
@@ -110,7 +110,11 @@ public:
 
     /// Overwrite this reference with another reference
     ref& operator=(const ref& r) {
-        print_copy_assigned(this, "pointer", r.m_ptr); track_copy_assigned((ref_tag*) this);
+        if (this == &r) {
+            return *this;
+        }
+        print_copy_assigned(this, "pointer", r.m_ptr);
+        track_copy_assigned((ref_tag *) this);
 
         if (m_ptr == r.m_ptr)
             return *this;
@@ -161,7 +165,7 @@ public:
     const T& operator*() const { return *m_ptr; }
 
     /// Return a pointer to the referenced object
-    operator T* () { return m_ptr; }
+    explicit operator T* () { return m_ptr; }
 
     /// Return a const pointer to the referenced object
     T* get_ptr() { return m_ptr; }

tests/pybind11_cross_module_tests.cpp

@@ -29,11 +29,14 @@ PYBIND11_MODULE(pybind11_cross_module_tests, m) {
     bind_local<ExternalType2>(m, "ExternalType2", py::module_local());
 
     // test_exceptions.py
+    py::register_local_exception<LocalSimpleException>(m, "LocalSimpleException");
     m.def("raise_runtime_error", []() { PyErr_SetString(PyExc_RuntimeError, "My runtime error"); throw py::error_already_set(); });
     m.def("raise_value_error", []() { PyErr_SetString(PyExc_ValueError, "My value error"); throw py::error_already_set(); });
     m.def("throw_pybind_value_error", []() { throw py::value_error("pybind11 value error"); });
     m.def("throw_pybind_type_error", []() { throw py::type_error("pybind11 type error"); });
     m.def("throw_stop_iteration", []() { throw py::stop_iteration(); });
+    m.def("throw_local_error", []() { throw LocalException("just local"); });
+    m.def("throw_local_simple_error", []() { throw LocalSimpleException("external mod"); });
     py::register_exception_translator([](std::exception_ptr p) {
       try {
           if (p) std::rethrow_exception(p);
@@ -42,6 +45,17 @@ PYBIND11_MODULE(pybind11_cross_module_tests, m) {
       }
     });
 
+    // translate the local exception into a key error but only in this module
+    py::register_local_exception_translator([](std::exception_ptr p) {
+      try {
+          if (p) {
+            std::rethrow_exception(p);
+          }
+      } catch (const LocalException &e) {
+        PyErr_SetString(PyExc_KeyError, e.what());
+      }
+    });
+
     // test_local_bindings.py
     // Local to both:
     bind_local<LocalType, 1>(m, "LocalType", py::module_local())
@@ -94,7 +108,7 @@ PYBIND11_MODULE(pybind11_cross_module_tests, m) {
     m.def("get_mixed_lg", [](int i) { return MixedLocalGlobal(i); });
 
     // test_internal_locals_differ
-    m.def("local_cpp_types_addr", []() { return (uintptr_t) &py::detail::registered_local_types_cpp(); });
+    m.def("local_cpp_types_addr", []() { return (uintptr_t) &py::detail::get_local_internals().registered_types_cpp; });
 
     // test_stl_caster_vs_stl_bind
     py::bind_vector<std::vector<int>>(m, "VectorInt");
@@ -109,7 +123,7 @@ PYBIND11_MODULE(pybind11_cross_module_tests, m) {
 
     class Dog : public pets::Pet {
     public:
-        Dog(std::string name) : Pet(std::move(name)) {}
+        explicit Dog(std::string name) : Pet(std::move(name)) {}
     };
     py::class_<pets::Pet>(m, "Pet", py::module_local())
         .def("name", &pets::Pet::name);

tests/pybind11_tests.h

 #pragma once
 
-// This must be kept first for MSVC 2015.
-// Do not remove the empty line between the #includes.
 #include <pybind11/pybind11.h>
-
 #include <pybind11/eval.h>
 
 #if defined(_MSC_VER) && _MSC_VER < 1910
@@ -19,15 +16,14 @@ class test_initializer {
     using Initializer = void (*)(py::module_ &);
 
 public:
-    test_initializer(Initializer init);
+    explicit test_initializer(Initializer init);
     test_initializer(const char *submodule_name, Initializer init);
 };
 
-#define TEST_SUBMODULE(name, variable)                   \
-    void test_submodule_##name(py::module_ &);            \
-    test_initializer name(#name, test_submodule_##name); \
-    void test_submodule_##name(py::module_ &variable)
-
+#define TEST_SUBMODULE(name, variable)                                                            \
+    void test_submodule_##name(py::module_ &);                                                    \
+    test_initializer name(#name, test_submodule_##name);                                          \
+    void test_submodule_##name(py::module_ &(variable))
 
 /// Dummy type which is not exported anywhere -- something to trigger a conversion error
 struct UnregisteredType { };
@@ -36,7 +32,7 @@ struct UnregisteredType { };
 class UserType {
 public:
     UserType() = default;
-    UserType(int i) : i(i) { }
+    explicit UserType(int i) : i(i) { }
 
     int value() const { return i; }
     void set(int set) { i = set; }

tests/requirements.txt

@@ -2,11 +2,11 @@
 numpy==1.16.6; python_version<"3.6" and sys_platform!="win32"
 numpy==1.18.0; platform_python_implementation=="PyPy" and sys_platform=="darwin" and python_version>="3.6"
 numpy==1.19.3; (platform_python_implementation!="PyPy" or sys_platform=="linux") and python_version=="3.6"
-numpy==1.20.0; (platform_python_implementation!="PyPy" or sys_platform=="linux") and python_version>="3.7" and python_version<"3.10"
+numpy==1.21.2; (platform_python_implementation!="PyPy" or sys_platform=="linux") and python_version>="3.7" and python_version<"3.10"
+numpy==1.21.2; platform_python_implementation!="PyPy" and sys_platform=="linux" and python_version=="3.10"
 pytest==4.6.9; python_version<"3.5"
 pytest==6.1.2; python_version=="3.5"
-pytest==6.2.1; python_version>="3.6" and python_version<="3.9"
-pytest @ git+https://github.com/pytest-dev/pytest@c117bc350ec1e570672fda3b2ad234fd52e72b53; python_version>="3.10"
+pytest==6.2.4; python_version>="3.6"
 pytest-timeout
 scipy==1.2.3; (platform_python_implementation!="PyPy" or sys_platform=="linux") and python_version<"3.6"
 scipy==1.5.4; (platform_python_implementation!="PyPy" or sys_platform=="linux") and python_version>="3.6" and python_version<"3.10"

tests/test_buffers.cpp

@@ -40,7 +40,11 @@ TEST_SUBMODULE(buffers, m) {
         }
 
         Matrix &operator=(const Matrix &s) {
-            print_copy_assigned(this, std::to_string(m_rows) + "x" + std::to_string(m_cols) + " matrix");
+            if (this == &s) {
+                return *this;
+            }
+            print_copy_assigned(this,
+                                std::to_string(m_rows) + "x" + std::to_string(m_cols) + " matrix");
             delete[] m_data;
             m_rows = s.m_rows;
             m_cols = s.m_cols;
@@ -118,7 +122,7 @@ TEST_SUBMODULE(buffers, m) {
     // test_inherited_protocol
     class SquareMatrix : public Matrix {
     public:
-        SquareMatrix(py::ssize_t n) : Matrix(n, n) { }
+        explicit SquareMatrix(py::ssize_t n) : Matrix(n, n) {}
     };
     // Derived classes inherit the buffer protocol and the buffer access function
     py::class_<SquareMatrix, Matrix>(m, "SquareMatrix")
@@ -169,7 +173,7 @@ TEST_SUBMODULE(buffers, m) {
 
     struct BufferReadOnly {
         const uint8_t value = 0;
-        BufferReadOnly(uint8_t value): value(value) {}
+        explicit BufferReadOnly(uint8_t value) : value(value) {}
 
         py::buffer_info get_buffer_info() {
             return py::buffer_info(&value, 1);

tests/test_buffers.py

 # -*- coding: utf-8 -*-
+import ctypes
 import io
 import struct
-import ctypes
 
 import pytest
 
 import env  # noqa: F401
-
-from pybind11_tests import buffers as m
 from pybind11_tests import ConstructorStats
+from pybind11_tests import buffers as m
 
 np = pytest.importorskip("numpy")
 

tests/test_builtin_casters.cpp

@@ -10,11 +10,6 @@
 #include "pybind11_tests.h"
 #include <pybind11/complex.h>
 
-#if defined(_MSC_VER)
-#  pragma warning(push)
-#  pragma warning(disable: 4127) // warning C4127: Conditional expression is constant
-#endif
-
 struct ConstRefCasted {
   int tag;
 };
@@ -30,16 +25,28 @@ class type_caster<ConstRefCasted> {
   // cast operator.
   bool load(handle, bool) { return true; }
 
-  operator ConstRefCasted &&() {
+  explicit operator ConstRefCasted &&() {
       value = {1};
       // NOLINTNEXTLINE(performance-move-const-arg)
       return std::move(value);
   }
-  operator ConstRefCasted&() { value = {2}; return value; }
-  operator ConstRefCasted*() { value = {3}; return &value; }
+  explicit operator ConstRefCasted &() {
+      value = {2};
+      return value;
+  }
+  explicit operator ConstRefCasted *() {
+      value = {3};
+      return &value;
+  }
 
-  operator const ConstRefCasted&() { value = {4}; return value; }
-  operator const ConstRefCasted*() { value = {5}; return &value; }
+  explicit operator const ConstRefCasted &() {
+      value = {4};
+      return value;
+  }
+  explicit operator const ConstRefCasted *() {
+      value = {5};
+      return &value;
+  }
 
   // custom cast_op to explicitly propagate types to the conversion operators.
   template <typename T_>
@@ -73,7 +80,7 @@ TEST_SUBMODULE(builtin_casters, m) {
     std::wstring wstr;
     wstr.push_back(0x61); // a
     wstr.push_back(0x2e18); // ⸘
-    if (sizeof(wchar_t) == 2) { wstr.push_back(mathbfA16_1); wstr.push_back(mathbfA16_2); } // 𝐀, utf16
+    if (PYBIND11_SILENCE_MSVC_C4127(sizeof(wchar_t) == 2)) { wstr.push_back(mathbfA16_1); wstr.push_back(mathbfA16_2); } // 𝐀, utf16
     else { wstr.push_back((wchar_t) mathbfA32); } // 𝐀, utf32
     wstr.push_back(0x7a); // z
 
@@ -83,11 +90,12 @@ TEST_SUBMODULE(builtin_casters, m) {
     m.def("good_wchar_string", [=]() { return wstr; }); // a‽𝐀z
     m.def("bad_utf8_string", []()  { return std::string("abc\xd0" "def"); });
     m.def("bad_utf16_string", [=]() { return std::u16string({ b16, char16_t(0xd800), z16 }); });
+#if PY_MAJOR_VERSION >= 3
     // Under Python 2.7, invalid unicode UTF-32 characters don't appear to trigger UnicodeDecodeError
-    if (PY_MAJOR_VERSION >= 3)
-        m.def("bad_utf32_string", [=]() { return std::u32string({ a32, char32_t(0xd800), z32 }); });
-    if (PY_MAJOR_VERSION >= 3 || sizeof(wchar_t) == 2)
+    m.def("bad_utf32_string", [=]() { return std::u32string({ a32, char32_t(0xd800), z32 }); });
+    if (PYBIND11_SILENCE_MSVC_C4127(sizeof(wchar_t) == 2))
         m.def("bad_wchar_string", [=]() { return std::wstring({ wchar_t(0x61), wchar_t(0xd800) }); });
+#endif
     m.def("u8_Z", []() -> char { return 'Z'; });
     m.def("u8_eacute", []() -> char { return '\xe9'; });
     m.def("u16_ibang", [=]() -> char16_t { return ib16; });

tests/test_builtin_casters.py

@@ -2,9 +2,8 @@
 import pytest
 
 import env  # noqa: F401
-
+from pybind11_tests import IncType, UserType
 from pybind11_tests import builtin_casters as m
-from pybind11_tests import UserType, IncType
 
 
 def test_simple_string():

tests/test_call_policies.py

@@ -2,9 +2,8 @@
 import pytest
 
 import env  # noqa: F401
-
-from pybind11_tests import call_policies as m
 from pybind11_tests import ConstructorStats
+from pybind11_tests import call_policies as m
 
 
 @pytest.mark.xfail("env.PYPY", reason="sometimes comes out 1 off on PyPy", strict=False)

tests/test_callbacks.cpp

@@ -81,16 +81,55 @@ TEST_SUBMODULE(callbacks, m) {
     };
     // Export the payload constructor statistics for testing purposes:
     m.def("payload_cstats", &ConstructorStats::get<Payload>);
-    /* Test cleanup of lambda closure */
-    m.def("test_cleanup", []() -> std::function<void()> {
+    m.def("test_lambda_closure_cleanup", []() -> std::function<void()> {
         Payload p;
 
+        // In this situation, `Func` in the implementation of
+        // `cpp_function::initialize` is NOT trivially destructible.
         return [p]() {
             /* p should be cleaned up when the returned function is garbage collected */
             (void) p;
         };
     });
 
+    class CppCallable {
+    public:
+        CppCallable() { track_default_created(this); }
+        ~CppCallable() { track_destroyed(this); }
+        CppCallable(const CppCallable &) { track_copy_created(this); }
+        CppCallable(CppCallable &&) noexcept { track_move_created(this); }
+        void operator()() {}
+    };
+
+    m.def("test_cpp_callable_cleanup", []() {
+        // Related issue: https://github.com/pybind/pybind11/issues/3228
+        // Related PR: https://github.com/pybind/pybind11/pull/3229
+        py::list alive_counts;
+        ConstructorStats &stat = ConstructorStats::get<CppCallable>();
+        alive_counts.append(stat.alive());
+        {
+            CppCallable cpp_callable;
+            alive_counts.append(stat.alive());
+            {
+                // In this situation, `Func` in the implementation of
+                // `cpp_function::initialize` IS trivially destructible,
+                // only `capture` is not.
+                py::cpp_function py_func(cpp_callable);
+                py::detail::silence_unused_warnings(py_func);
+                alive_counts.append(stat.alive());
+            }
+            alive_counts.append(stat.alive());
+            {
+                py::cpp_function py_func(std::move(cpp_callable));
+                py::detail::silence_unused_warnings(py_func);
+                alive_counts.append(stat.alive());
+            }
+            alive_counts.append(stat.alive());
+        }
+        alive_counts.append(stat.alive());
+        return alive_counts;
+    });
+
     // test_cpp_function_roundtrip
     /* Test if passing a function pointer from C++ -> Python -> C++ yields the original pointer */
     m.def("dummy_function", &dummy_function);

tests/test_callbacks.py

 # -*- coding: utf-8 -*-
-import pytest
-from pybind11_tests import callbacks as m
-from threading import Thread
 import time
+from threading import Thread
+
+import pytest
+
 import env  # NOQA: F401
+from pybind11_tests import callbacks as m
 
 
 def test_callbacks():
@@ -77,13 +79,18 @@ def test_keyword_args_and_generalized_unpacking():
 
 
 def test_lambda_closure_cleanup():
-    m.test_cleanup()
+    m.test_lambda_closure_cleanup()
     cstats = m.payload_cstats()
     assert cstats.alive() == 0
     assert cstats.copy_constructions == 1
     assert cstats.move_constructions >= 1
 
 
+def test_cpp_callable_cleanup():
+    alive_counts = m.test_cpp_callable_cleanup()
+    assert alive_counts == [0, 1, 2, 1, 2, 1, 0]
+
+
 def test_cpp_function_roundtrip():
     """Test if passing a function pointer from C++ -> Python -> C++ yields the original pointer"""
 

tests/test_chrono.py

 # -*- coding: utf-8 -*-
-from pybind11_tests import chrono as m
 import datetime
+
 import pytest
 
 import env  # noqa: F401
+from pybind11_tests import chrono as m
 
 
 def test_chrono_system_clock():

tests/test_class.cpp

@@ -27,7 +27,7 @@
 
 // test_brace_initialization
 struct NoBraceInitialization {
-    NoBraceInitialization(std::vector<int> v) : vec{std::move(v)} {}
+    explicit NoBraceInitialization(std::vector<int> v) : vec{std::move(v)} {}
     template <typename T>
     NoBraceInitialization(std::initializer_list<T> l) : vec(l) {}
 
@@ -47,10 +47,26 @@ TEST_SUBMODULE(class_, m) {
         }
         ~NoConstructor() { print_destroyed(this); }
     };
+    struct NoConstructorNew {
+        NoConstructorNew() = default;
+        NoConstructorNew(const NoConstructorNew &) = default;
+        NoConstructorNew(NoConstructorNew &&) = default;
+        static NoConstructorNew *new_instance() {
+            auto *ptr = new NoConstructorNew();
+            print_created(ptr, "via new_instance");
+            return ptr;
+        }
+        ~NoConstructorNew() { print_destroyed(this); }
+    };
 
     py::class_<NoConstructor>(m, "NoConstructor")
         .def_static("new_instance", &NoConstructor::new_instance, "Return an instance");
 
+    py::class_<NoConstructorNew>(m, "NoConstructorNew")
+        .def(py::init([](const NoConstructorNew &self) { return self; })) // Need a NOOP __init__
+        .def_static("__new__",
+                    [](const py::object &) { return NoConstructorNew::new_instance(); });
+
     // test_inheritance
     class Pet {
     public:
@@ -65,18 +81,18 @@ TEST_SUBMODULE(class_, m) {
 
     class Dog : public Pet {
     public:
-        Dog(const std::string &name) : Pet(name, "dog") {}
+        explicit Dog(const std::string &name) : Pet(name, "dog") {}
         std::string bark() const { return "Woof!"; }
     };
 
     class Rabbit : public Pet {
     public:
-        Rabbit(const std::string &name) : Pet(name, "parrot") {}
+        explicit Rabbit(const std::string &name) : Pet(name, "parrot") {}
     };
 
     class Hamster : public Pet {
     public:
-        Hamster(const std::string &name) : Pet(name, "rodent") {}
+        explicit Hamster(const std::string &name) : Pet(name, "rodent") {}
     };
 
     class Chimera : public Pet {
@@ -208,7 +224,7 @@ TEST_SUBMODULE(class_, m) {
     struct ConvertibleFromUserType {
         int i;
 
-        ConvertibleFromUserType(UserType u) : i(u.value()) { }
+        explicit ConvertibleFromUserType(UserType u) : i(u.value()) {}
     };
 
     py::class_<ConvertibleFromUserType>(m, "AcceptsUserType")
@@ -263,7 +279,7 @@ TEST_SUBMODULE(class_, m) {
     };
     struct PyAliasedHasOpNewDelSize : AliasedHasOpNewDelSize {
         PyAliasedHasOpNewDelSize() = default;
-        PyAliasedHasOpNewDelSize(int) { }
+        explicit PyAliasedHasOpNewDelSize(int) {}
         std::uint64_t j;
     };
     struct HasOpNewDelBoth {
@@ -492,15 +508,15 @@ using DoesntBreak5 = py::class_<BreaksBase<5>>;
 using DoesntBreak6 = py::class_<BreaksBase<6>, std::shared_ptr<BreaksBase<6>>, BreaksTramp<6>>;
 using DoesntBreak7 = py::class_<BreaksBase<7>, BreaksTramp<7>, std::shared_ptr<BreaksBase<7>>>;
 using DoesntBreak8 = py::class_<BreaksBase<8>, std::shared_ptr<BreaksBase<8>>>;
-#define CHECK_BASE(N) static_assert(std::is_same<typename DoesntBreak##N::type, BreaksBase<N>>::value, \
+#define CHECK_BASE(N) static_assert(std::is_same<typename DoesntBreak##N::type, BreaksBase<(N)>>::value, \
         "DoesntBreak" #N " has wrong type!")
 CHECK_BASE(1); CHECK_BASE(2); CHECK_BASE(3); CHECK_BASE(4); CHECK_BASE(5); CHECK_BASE(6); CHECK_BASE(7); CHECK_BASE(8);
-#define CHECK_ALIAS(N) static_assert(DoesntBreak##N::has_alias && std::is_same<typename DoesntBreak##N::type_alias, BreaksTramp<N>>::value, \
+#define CHECK_ALIAS(N) static_assert(DoesntBreak##N::has_alias && std::is_same<typename DoesntBreak##N::type_alias, BreaksTramp<(N)>>::value, \
         "DoesntBreak" #N " has wrong type_alias!")
 #define CHECK_NOALIAS(N) static_assert(!DoesntBreak##N::has_alias && std::is_void<typename DoesntBreak##N::type_alias>::value, \
         "DoesntBreak" #N " has type alias, but shouldn't!")
 CHECK_ALIAS(1); CHECK_ALIAS(2); CHECK_NOALIAS(3); CHECK_ALIAS(4); CHECK_NOALIAS(5); CHECK_ALIAS(6); CHECK_ALIAS(7); CHECK_NOALIAS(8);
-#define CHECK_HOLDER(N, TYPE) static_assert(std::is_same<typename DoesntBreak##N::holder_type, std::TYPE##_ptr<BreaksBase<N>>>::value, \
+#define CHECK_HOLDER(N, TYPE) static_assert(std::is_same<typename DoesntBreak##N::holder_type, std::TYPE##_ptr<BreaksBase<(N)>>>::value, \
         "DoesntBreak" #N " has wrong holder_type!")
 CHECK_HOLDER(1, unique); CHECK_HOLDER(2, unique); CHECK_HOLDER(3, unique); CHECK_HOLDER(4, unique); CHECK_HOLDER(5, unique);
 CHECK_HOLDER(6, shared); CHECK_HOLDER(7, shared); CHECK_HOLDER(8, shared);
@@ -510,7 +526,7 @@ CHECK_HOLDER(6, shared); CHECK_HOLDER(7, shared); CHECK_HOLDER(8, shared);
 // failures occurs).
 
 // We have to actually look into the type: the typedef alone isn't enough to instantiate the type:
-#define CHECK_BROKEN(N) static_assert(std::is_same<typename Breaks##N::type, BreaksBase<-N>>::value, \
+#define CHECK_BROKEN(N) static_assert(std::is_same<typename Breaks##N::type, BreaksBase<-(N)>>::value, \
         "Breaks1 has wrong type!");
 
 //// Two holder classes:

tests/test_class.py

@@ -2,9 +2,8 @@
 import pytest
 
 import env  # noqa: F401
-
+from pybind11_tests import ConstructorStats, UserType
 from pybind11_tests import class_ as m
-from pybind11_tests import UserType, ConstructorStats
 
 
 def test_repr():
@@ -26,6 +25,14 @@ def test_instance(msg):
     assert cstats.alive() == 0
 
 
+def test_instance_new(msg):
+    instance = m.NoConstructorNew()  # .__new__(m.NoConstructor.__class__)
+    cstats = ConstructorStats.get(m.NoConstructorNew)
+    assert cstats.alive() == 1
+    del instance
+    assert cstats.alive() == 0
+
+
 def test_type():
     assert m.check_type(1) == m.DerivedClass1
     with pytest.raises(RuntimeError) as execinfo:

tests/test_cmake_build/installed_embed/CMakeLists.txt

@@ -22,5 +22,7 @@ set_target_properties(test_installed_embed PROPERTIES OUTPUT_NAME test_cmake_bui
 # This may be needed to resolve header conflicts, e.g. between Python release and debug headers.
 set_target_properties(test_installed_embed PROPERTIES NO_SYSTEM_FROM_IMPORTED ON)
 
-add_custom_target(check_installed_embed $<TARGET_FILE:test_installed_embed>
-                                        ${PROJECT_SOURCE_DIR}/../test.py)
+add_custom_target(
+  check_installed_embed
+  $<TARGET_FILE:test_installed_embed> ${PROJECT_SOURCE_DIR}/../test.py
+  DEPENDS test_installed_embed)