Merge branch 'master' into sh_merge_master

.clang-tidy

@@ -25,11 +25,12 @@ modernize-replace-random-shuffle,
 modernize-shrink-to-fit,
 modernize-use-auto,
 modernize-use-bool-literals,
+modernize-use-default-member-init,
 modernize-use-equals-default,
 modernize-use-equals-delete,
-modernize-use-default-member-init,
-modernize-use-noexcept,
 modernize-use-emplace,
+modernize-use-noexcept,
+modernize-use-nullptr,
 modernize-use-override,
 modernize-use-using,
 *performance*,

.github/dependabot.yml

@@ -7,10 +7,5 @@ updates:
       interval: "daily"
     ignore:
       # Official actions have moving tags like v1
-      # that are used, so they don't need updates here
+      - dependency-name: "actions/*"
-      - dependency-name: "actions/checkout"
+        update-types: ["version-update:semver-minor", "version-update:semver-patch"]
-      - dependency-name: "actions/setup-python"
-      - dependency-name: "actions/cache"
-      - dependency-name: "actions/upload-artifact"
-      - dependency-name: "actions/download-artifact"
-      - dependency-name: "actions/labeler"

.github/workflows/ci.yml

@@ -63,10 +63,10 @@ jobs:
     runs-on: ${{ matrix.runs-on }}
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
 
     - name: Setup Python ${{ matrix.python }}
-      uses: actions/setup-python@v2
+      uses: actions/setup-python@v3
       with:
         python-version: ${{ matrix.python }}
 
@@ -84,7 +84,7 @@ jobs:
 
     - name: Cache wheels
       if: runner.os == 'macOS'
-      uses: actions/cache@v2
+      uses: actions/cache@v3
       with:
         # This path is specific to macOS - we really only need it for PyPy NumPy wheels
         # See https://github.com/actions/cache/blob/master/examples.md#python---pip
@@ -193,7 +193,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
 
     - name: Setup Python ${{ matrix.python-version }} (deadsnakes)
       uses: deadsnakes/action@v2.1.1
@@ -206,7 +206,7 @@ jobs:
 
     - name: Valgrind cache
       if: matrix.valgrind
-      uses: actions/cache@v2
+      uses: actions/cache@v3
       id: cache-valgrind
       with:
         path: valgrind
@@ -286,7 +286,7 @@ jobs:
     container: "silkeh/clang:${{ matrix.clang }}"
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
 
     - name: Add wget and python3
       run: apt-get update && apt-get install -y python3-dev python3-numpy python3-pytest libeigen3-dev
@@ -320,7 +320,7 @@ jobs:
     container: nvidia/cuda:11.0-devel-ubuntu20.04
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
 
     # tzdata will try to ask for the timezone, so set the DEBIAN_FRONTEND
     - name: Install 🐍 3
@@ -344,7 +344,7 @@ jobs:
 #    container: centos:8
 #
 #    steps:
-#    - uses: actions/checkout@v2
+#    - uses: actions/checkout@v3
 #
 #    - name: Add Python 3 and a few requirements
 #      run: yum update -y && yum install -y git python3-devel python3-numpy python3-pytest make environment-modules
@@ -387,7 +387,7 @@ jobs:
     container: centos:7
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
 
     - name: Add Python 3 and a few requirements
       run: yum update -y && yum install -y epel-release && yum install -y git python3-devel make environment-modules cmake3
@@ -448,7 +448,7 @@ jobs:
     container: "gcc:${{ matrix.gcc }}"
 
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v3
 
     - name: Add Python 3
       run: apt-get update; apt-get install -y python3-dev python3-numpy python3-pytest python3-pip libeigen3-dev
@@ -490,7 +490,7 @@ jobs:
     name: "🐍 3 • ICC latest • x64"
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
 
     - name: Add apt repo
       run: |
@@ -593,7 +593,7 @@ jobs:
     container: "quay.io/centos/centos:${{ matrix.centos }}"
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
 
     - name: Add Python 3
       run: yum update -y && yum install -y python3-devel gcc-c++ make git
@@ -636,7 +636,7 @@ jobs:
     container: i386/debian:buster
 
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v3
 
     - name: Install requirements
       run: |
@@ -679,9 +679,9 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
 
-    - uses: actions/setup-python@v2
+    - uses: actions/setup-python@v3
 
     - name: Install Doxygen
       run: sudo apt-get install -y doxygen librsvg2-bin # Changed to rsvg-convert in 20.04
@@ -726,10 +726,10 @@ jobs:
     runs-on: windows-2019
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
 
     - name: Setup Python ${{ matrix.python }}
-      uses: actions/setup-python@v2
+      uses: actions/setup-python@v3
       with:
         python-version: ${{ matrix.python }}
         architecture: x86
@@ -779,10 +779,10 @@ jobs:
     runs-on: windows-2019
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
 
     - name: Setup Python ${{ matrix.python }}
-      uses: actions/setup-python@v2
+      uses: actions/setup-python@v3
       with:
         python-version: ${{ matrix.python }}
         architecture: x86
@@ -827,10 +827,10 @@ jobs:
     runs-on: windows-2022
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
 
     - name: Setup Python ${{ matrix.python }}
-      uses: actions/setup-python@v2
+      uses: actions/setup-python@v3
       with:
         python-version: ${{ matrix.python }}
 
@@ -890,7 +890,7 @@ jobs:
           mingw-w64-${{matrix.env}}-boost
           mingw-w64-${{matrix.env}}-catch
 
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
 
     - name: Configure C++11
       # LTO leads to many undefined reference like

.github/workflows/configure.yml

@@ -38,10 +38,10 @@ jobs:
     runs-on: ${{ matrix.runs-on }}
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
 
     - name: Setup Python 3.7
-      uses: actions/setup-python@v2
+      uses: actions/setup-python@v3
       with:
         python-version: 3.7
         architecture: ${{ matrix.arch }}

.github/workflows/format.yml

@@ -21,8 +21,8 @@ jobs:
     name: Format
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
-    - uses: actions/setup-python@v2
+    - uses: actions/setup-python@v3
     - name: Add matchers
       run: echo "::add-matcher::$GITHUB_WORKSPACE/.github/matchers/pylint.json"
     - uses: pre-commit/action@v2.0.3
@@ -37,7 +37,7 @@ jobs:
     runs-on: ubuntu-latest
     container: silkeh/clang:12
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
 
     - name: Install requirements
       run: apt-get update && apt-get install -y python3-dev python3-pytest

.github/workflows/pip.yml

@@ -25,10 +25,10 @@ jobs:
     runs-on: windows-latest
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
 
     - name: Setup 🐍 3.6
-      uses: actions/setup-python@v2
+      uses: actions/setup-python@v3
       with:
         python-version: 3.6
 
@@ -47,10 +47,10 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
 
     - name: Setup 🐍 3.8
-      uses: actions/setup-python@v2
+      uses: actions/setup-python@v3
       with:
         python-version: 3.8
 
@@ -70,13 +70,13 @@ jobs:
       run: twine check dist/*
 
     - name: Save standard package
-      uses: actions/upload-artifact@v2
+      uses: actions/upload-artifact@v3
       with:
         name: standard
         path: dist/pybind11-*
 
     - name: Save global package
-      uses: actions/upload-artifact@v2
+      uses: actions/upload-artifact@v3
       with:
         name: global
         path: dist/pybind11_global-*
@@ -91,10 +91,10 @@ jobs:
     needs: [packaging]
 
     steps:
-    - uses: actions/setup-python@v2
+    - uses: actions/setup-python@v3
 
     # Downloads all to directories matching the artifact names
-    - uses: actions/download-artifact@v2
+    - uses: actions/download-artifact@v3
 
     - name: Publish standard package
       uses: pypa/gh-action-pypi-publish@v1.5.0

.github/workflows/upstream.yml

@@ -19,10 +19,10 @@ jobs:
     if: "contains(github.event.pull_request.labels.*.name, 'python dev')"
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
 
     - name: Setup Python 3.11
-      uses: actions/setup-python@v2
+      uses: actions/setup-python@v3
       with:
         python-version: "3.11-dev"
 

.pre-commit-config.yaml

@@ -73,7 +73,7 @@ repos:
 
 # Autoremoves unused imports
 - repo: https://github.com/hadialqattan/pycln
-  rev: "v1.2.5"
+  rev: "v1.3.1"
   hooks:
   - id: pycln
     stages: [manual]
@@ -167,7 +167,7 @@ repos:
 
 # Clang format the codebase automatically
 - repo: https://github.com/pre-commit/mirrors-clang-format
-  rev: "v13.0.1"
+  rev: "v14.0.1"
   hooks:
   - id: clang-format
     types_or: [c++, c, cuda]

include/pybind11/attr.h

@@ -10,6 +10,7 @@
 
 #pragma once
 
+#include "detail/common.h"
 #include "cast.h"
 
 #include <functional>
@@ -477,7 +478,7 @@ struct process_attribute<arg_v> : process_attribute_default<arg_v> {
         }
 
         if (!a.value) {
-#if !defined(NDEBUG)
+#if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
             std::string descr("'");
             if (a.name) {
                 descr += std::string(a.name) + ": ";
@@ -498,7 +499,8 @@ struct process_attribute<arg_v> : process_attribute_default<arg_v> {
 #else
             pybind11_fail("arg(): could not convert default argument "
                           "into a Python object (type not registered yet?). "
-                          "Compile in debug mode for more information.");
+                          "#define PYBIND11_DETAILED_ERROR_MESSAGES or compile in debug mode for "
+                          "more information.");
 #endif
         }
         r->args.emplace_back(a.name, a.descr, a.value.inc_ref(), !a.flag_noconvert, a.flag_none);

include/pybind11/cast.h

@@ -798,8 +798,9 @@ protected:
             return true;
         }
         throw cast_error("Unable to cast from non-held to held instance (T& to Holder<T>) "
-#if defined(NDEBUG)
+#if !defined(PYBIND11_DETAILED_ERROR_MESSAGES)
-                         "(compile in debug mode for type information)");
+                         "(#define PYBIND11_DETAILED_ERROR_MESSAGES or compile in debug mode for "
+                         "type information)");
 #else
                          "of type '"
                          + type_id<holder_type>() + "''");
@@ -1029,9 +1030,9 @@ struct return_value_policy_override<
 template <typename T, typename SFINAE>
 type_caster<T, SFINAE> &load_type(type_caster<T, SFINAE> &conv, const handle &handle) {
     if (!conv.load(handle, true)) {
-#if defined(NDEBUG)
+#if !defined(PYBIND11_DETAILED_ERROR_MESSAGES)
-        throw cast_error(
+        throw cast_error("Unable to cast Python instance to C++ type (#define "
-            "Unable to cast Python instance to C++ type (compile in debug mode for details)");
+                         "PYBIND11_DETAILED_ERROR_MESSAGES or compile in debug mode for details)");
 #else
         throw cast_error("Unable to cast Python instance of type "
                          + (std::string) str(type::handle_of(handle)) + " to C++ type '"
@@ -1096,10 +1097,10 @@ inline void handle::cast() const {
 template <typename T>
 detail::enable_if_t<!detail::move_never<T>::value, T> move(object &&obj) {
     if (obj.ref_count() > 1) {
-#if defined(NDEBUG)
+#if !defined(PYBIND11_DETAILED_ERROR_MESSAGES)
         throw cast_error(
             "Unable to cast Python instance to C++ rvalue: instance has multiple references"
-            " (compile in debug mode for details)");
+            " (#define PYBIND11_DETAILED_ERROR_MESSAGES or compile in debug mode for details)");
 #else
         throw cast_error("Unable to move from Python " + (std::string) str(type::handle_of(obj))
                          + " instance to C++ " + type_id<T>()
@@ -1200,10 +1201,10 @@ PYBIND11_NAMESPACE_END(detail)
 
 // The overloads could coexist, i.e. the #if is not strictly speaking needed,
 // but it is an easy minor optimization.
-#if defined(NDEBUG)
+#if !defined(PYBIND11_DETAILED_ERROR_MESSAGES)
 inline cast_error cast_error_unable_to_convert_call_arg() {
-    return cast_error(
+    return cast_error("Unable to convert call argument to Python object (#define "
-        "Unable to convert call argument to Python object (compile in debug mode for details)");
+                      "PYBIND11_DETAILED_ERROR_MESSAGES or compile in debug mode for details)");
 }
 #else
 inline cast_error cast_error_unable_to_convert_call_arg(const std::string &name,
@@ -1225,7 +1226,7 @@ tuple make_tuple(Args &&...args_) {
         detail::make_caster<Args>::cast(std::forward<Args>(args_), policy, nullptr))...}};
     for (size_t i = 0; i < args.size(); i++) {
         if (!args[i]) {
-#if defined(NDEBUG)
+#if !defined(PYBIND11_DETAILED_ERROR_MESSAGES)
             throw cast_error_unable_to_convert_call_arg();
 #else
             std::array<std::string, size> argtypes{{type_id<Args>()...}};
@@ -1277,7 +1278,7 @@ private:
         : arg(base), value(reinterpret_steal<object>(detail::make_caster<T>::cast(
                          std::forward<T>(x), return_value_policy::automatic, {}))),
           descr(descr)
-#if !defined(NDEBUG)
+#if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
           ,
           type(type_id<T>())
 #endif
@@ -1317,7 +1318,7 @@ public:
     object value;
     /// The (optional) description of the default value
     const char *descr;
-#if !defined(NDEBUG)
+#if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
     /// The C++ type name of the default value (only available when compiled in debug mode)
     std::string type;
 #endif
@@ -1515,7 +1516,7 @@ private:
         auto o = reinterpret_steal<object>(
             detail::make_caster<T>::cast(std::forward<T>(x), policy, {}));
         if (!o) {
-#if defined(NDEBUG)
+#if !defined(PYBIND11_DETAILED_ERROR_MESSAGES)
             throw cast_error_unable_to_convert_call_arg();
 #else
             throw cast_error_unable_to_convert_call_arg(std::to_string(args_list.size()),
@@ -1533,21 +1534,21 @@ private:
 
     void process(list & /*args_list*/, arg_v a) {
         if (!a.name) {
-#if defined(NDEBUG)
+#if !defined(PYBIND11_DETAILED_ERROR_MESSAGES)
             nameless_argument_error();
 #else
             nameless_argument_error(a.type);
 #endif
         }
         if (m_kwargs.contains(a.name)) {
-#if defined(NDEBUG)
+#if !defined(PYBIND11_DETAILED_ERROR_MESSAGES)
             multiple_values_error();
 #else
             multiple_values_error(a.name);
 #endif
         }
         if (!a.value) {
-#if defined(NDEBUG)
+#if !defined(PYBIND11_DETAILED_ERROR_MESSAGES)
             throw cast_error_unable_to_convert_call_arg();
 #else
             throw cast_error_unable_to_convert_call_arg(a.name, a.type);
@@ -1562,7 +1563,7 @@ private:
         }
         for (auto k : reinterpret_borrow<dict>(kp)) {
             if (m_kwargs.contains(k.first)) {
-#if defined(NDEBUG)
+#if !defined(PYBIND11_DETAILED_ERROR_MESSAGES)
                 multiple_values_error();
 #else
                 multiple_values_error(str(k.first));
@@ -1573,9 +1574,10 @@ private:
     }
 
     [[noreturn]] static void nameless_argument_error() {
-        throw type_error("Got kwargs without a name; only named arguments "
+        throw type_error(
-                         "may be passed via py::arg() to a python function call. "
+            "Got kwargs without a name; only named arguments "
-                         "(compile in debug mode for details)");
+            "may be passed via py::arg() to a python function call. "
+            "(#define PYBIND11_DETAILED_ERROR_MESSAGES or compile in debug mode for details)");
     }
     [[noreturn]] static void nameless_argument_error(const std::string &type) {
         throw type_error("Got kwargs without a name of type '" + type
@@ -1583,8 +1585,9 @@ private:
                            "arguments may be passed via py::arg() to a python function call. ");
     }
     [[noreturn]] static void multiple_values_error() {
-        throw type_error("Got multiple values for keyword argument "
+        throw type_error(
-                         "(compile in debug mode for details)");
+            "Got multiple values for keyword argument "
+            "(#define PYBIND11_DETAILED_ERROR_MESSAGES or compile in debug mode for details)");
     }
 
     [[noreturn]] static void multiple_values_error(const std::string &name) {
@@ -1631,7 +1634,7 @@ unpacking_collector<policy> collect_arguments(Args &&...args) {
 template <typename Derived>
 template <return_value_policy policy, typename... Args>
 object object_api<Derived>::operator()(Args &&...args) const {
-#ifndef NDEBUG
+#if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
     if (!PyGILState_Check()) {
         pybind11_fail("pybind11::object_api<>::operator() PyGILState_Check() failure.");
     }

include/pybind11/detail/common.h

@@ -1169,5 +1169,12 @@ constexpr inline bool silence_msvc_c4127(bool cond) { return cond; }
 #    define PYBIND11_SILENCE_MSVC_C4127(...) __VA_ARGS__
 #endif
 
+// Pybind offers detailed error messages by default for all builts that are debug (through the
+// negation of ndebug). This can also be manually enabled by users, for any builds, through
+// defining PYBIND11_DETAILED_ERROR_MESSAGES.
+#if !defined(PYBIND11_DETAILED_ERROR_MESSAGES) && !defined(NDEBUG)
+#    define PYBIND11_DETAILED_ERROR_MESSAGES
+#endif
+
 PYBIND11_NAMESPACE_END(detail)
 PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

include/pybind11/detail/type_caster_base.h

@@ -394,15 +394,16 @@ instance::get_value_and_holder(const type_info *find_type /*= nullptr default in
         return value_and_holder();
     }
 
-#if defined(NDEBUG)
+#if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
-    pybind11_fail("pybind11::detail::instance::get_value_and_holder: "
-                  "type is not a pybind11 base of the given instance "
-                  "(compile in debug mode for type details)");
-#else
     pybind11_fail("pybind11::detail::instance::get_value_and_holder: `"
                   + get_fully_qualified_tp_name(find_type->type)
                   + "' is not a pybind11 base of the given `"
                   + get_fully_qualified_tp_name(Py_TYPE(this)) + "' instance");
+#else
+    pybind11_fail(
+        "pybind11::detail::instance::get_value_and_holder: "
+        "type is not a pybind11 base of the given instance "
+        "(#define PYBIND11_DETAILED_ERROR_MESSAGES or compile in debug mode for type details)");
 #endif
 }
 
@@ -612,14 +613,15 @@ public:
                 if (copy_constructor) {
                     valueptr = copy_constructor(src);
                 } else {
-#if defined(NDEBUG)
+#if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
-                    throw cast_error("return_value_policy = copy, but type is "
-                                     "non-copyable! (compile in debug mode for details)");
-#else
                     std::string type_name(tinfo->cpptype->name());
                     detail::clean_type_id(type_name);
                     throw cast_error("return_value_policy = copy, but type " + type_name
                                      + " is non-copyable!");
+#else
+                    throw cast_error("return_value_policy = copy, but type is "
+                                     "non-copyable! (#define PYBIND11_DETAILED_ERROR_MESSAGES or "
+                                     "compile in debug mode for details)");
 #endif
                 }
                 wrapper->owned = true;
@@ -631,15 +633,16 @@ public:
                 } else if (copy_constructor) {
                     valueptr = copy_constructor(src);
                 } else {
-#if defined(NDEBUG)
+#if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
-                    throw cast_error("return_value_policy = move, but type is neither "
-                                     "movable nor copyable! "
-                                     "(compile in debug mode for details)");
-#else
                     std::string type_name(tinfo->cpptype->name());
                     detail::clean_type_id(type_name);
                     throw cast_error("return_value_policy = move, but type " + type_name
                                      + " is neither movable nor copyable!");
+#else
+                    throw cast_error("return_value_policy = move, but type is neither "
+                                     "movable nor copyable! "
+                                     "(#define PYBIND11_DETAILED_ERROR_MESSAGES or compile in "
+                                     "debug mode for details)");
 #endif
                 }
                 wrapper->owned = true;

include/pybind11/gil.h

@@ -62,7 +62,7 @@ public:
 
         if (!tstate) {
             tstate = PyThreadState_New(internals.istate);
-#    if !defined(NDEBUG)
+#    if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
             if (!tstate) {
                 pybind11_fail("scoped_acquire: could not create thread state!");
             }
@@ -84,7 +84,7 @@ public:
 
     PYBIND11_NOINLINE void dec_ref() {
         --tstate->gilstate_counter;
-#    if !defined(NDEBUG)
+#    if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
         if (detail::get_thread_state_unchecked() != tstate) {
             pybind11_fail("scoped_acquire::dec_ref(): thread state must be current!");
         }
@@ -93,7 +93,7 @@ public:
         }
 #    endif
         if (tstate->gilstate_counter == 0) {
-#    if !defined(NDEBUG)
+#    if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
             if (!release) {
                 pybind11_fail("scoped_acquire::dec_ref(): internal error!");
             }

include/pybind11/numpy.h

@@ -263,7 +263,7 @@ private:
     static npy_api lookup() {
         module_ m = module_::import("numpy.core.multiarray");
         auto c = m.attr("_ARRAY_API");
-        void **api_ptr = (void **) PyCapsule_GetPointer(c.ptr(), NULL);
+        void **api_ptr = (void **) PyCapsule_GetPointer(c.ptr(), nullptr);
         npy_api api;
 #define DECL_NPY_API(Func) api.Func##_ = (decltype(api.Func##_)) api_ptr[API_##Func];
         DECL_NPY_API(PyArray_GetNDArrayCFeatureVersion);
@@ -547,9 +547,11 @@ public:
                     .ptr();
     }
 
-    explicit dtype(const std::string &format) : dtype(from_args(pybind11::str(format))) {}
+    explicit dtype(const pybind11::str &format) : dtype(from_args(format)) {}
 
-    explicit dtype(const char *format) : dtype(from_args(pybind11::str(format))) {}
+    explicit dtype(const std::string &format) : dtype(pybind11::str(format)) {}
+
+    explicit dtype(const char *format) : dtype(pybind11::str(format)) {}
 
     dtype(list names, list formats, list offsets, ssize_t itemsize) {
         dict args;
@@ -557,7 +559,7 @@ public:
         args["formats"] = std::move(formats);
         args["offsets"] = std::move(offsets);
         args["itemsize"] = pybind11::int_(itemsize);
-        m_ptr = from_args(std::move(args)).release().ptr();
+        m_ptr = from_args(args).release().ptr();
     }
 
     explicit dtype(int typenum)
@@ -568,7 +570,7 @@ public:
     }
 
     /// This is essentially the same as calling numpy.dtype(args) in Python.
-    static dtype from_args(object args) {
+    static dtype from_args(const object &args) {
         PyObject *ptr = nullptr;
         if ((detail::npy_api::get().PyArray_DescrConverter_(args.ptr(), &ptr) == 0) || !ptr) {
             throw error_already_set();
@@ -645,8 +647,9 @@ private:
         for (auto field : attr("fields").attr("items")()) {
             auto spec = field.cast<tuple>();
             auto name = spec[0].cast<pybind11::str>();
-            auto format = spec[1].cast<tuple>()[0].cast<dtype>();
+            auto spec_fo = spec[1].cast<tuple>();
-            auto offset = spec[1].cast<tuple>()[1].cast<pybind11::int_>();
+            auto format = spec_fo[0].cast<dtype>();
+            auto offset = spec_fo[1].cast<pybind11::int_>();
             if ((len(name) == 0u) && format.kind() == 'V') {
                 continue;
             }
@@ -1549,7 +1552,7 @@ public:
     void *data() const { return p_ptr; }
 
 private:
-    char *p_ptr{0};
+    char *p_ptr{nullptr};
     container_type m_strides;
 };
 

include/pybind11/pybind11.h

@@ -313,6 +313,10 @@ protected:
     // along the way.
     class strdup_guard {
     public:
+        strdup_guard() = default;
+        strdup_guard(const strdup_guard &) = delete;
+        strdup_guard &operator=(const strdup_guard &) = delete;
+
         ~strdup_guard() {
             for (auto *s : strings) {
                 std::free(s);
@@ -367,7 +371,7 @@ protected:
         rec->is_constructor = (std::strcmp(rec->name, "__init__") == 0)
                               || (std::strcmp(rec->name, "__setstate__") == 0);
 
-#if !defined(NDEBUG) && !defined(PYBIND11_DISABLE_NEW_STYLE_INIT_WARNING)
+#if defined(PYBIND11_DETAILED_ERROR_MESSAGES) && !defined(PYBIND11_DISABLE_NEW_STYLE_INIT_WARNING)
         if (rec->is_constructor && !rec->is_new_style_constructor) {
             const auto class_name
                 = detail::get_fully_qualified_tp_name((PyTypeObject *) rec->scope.ptr());
@@ -515,8 +519,9 @@ protected:
             if (chain->is_method != rec->is_method) {
                 pybind11_fail(
                     "overloading a method with both static and instance methods is not supported; "
-#if defined(NDEBUG)
+#if !defined(PYBIND11_DETAILED_ERROR_MESSAGES)
-                    "compile in debug mode for more details"
+                    "#define PYBIND11_DETAILED_ERROR_MESSAGES or compile in debug mode for more "
+                    "details"
 #else
                     "error while attempting to bind "
                     + std::string(rec->is_method ? "instance" : "static") + " method "
@@ -903,7 +908,7 @@ protected:
 
 // 5. Put everything in a vector.  Not technically step 5, we've been building it
 // in `call.args` all along.
-#if !defined(NDEBUG)
+#if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
                 if (call.args.size() != func.nargs || call.args_convert.size() != func.nargs) {
                     pybind11_fail("Internal error: function call dispatcher inserted wrong number "
                                   "of arguments!");
@@ -2592,7 +2597,7 @@ public:
     exception(handle scope, const char *name, handle base = PyExc_Exception) {
         std::string full_name
             = scope.attr("__name__").cast<std::string>() + std::string(".") + name;
-        m_ptr = PyErr_NewException(const_cast<char *>(full_name.c_str()), base.ptr(), NULL);
+        m_ptr = PyErr_NewException(const_cast<char *>(full_name.c_str()), base.ptr(), nullptr);
         if (hasattr(scope, "__dict__") && scope.attr("__dict__").contains(name)) {
             pybind11_fail("Error during initialization: multiple incompatible "
                           "definitions with name \""

include/pybind11/pytypes.h

@@ -600,13 +600,13 @@ inline handle get_function(handle value) {
 inline PyObject *dict_getitemstring(PyObject *v, const char *key) {
     PyObject *kv = nullptr, *rv = nullptr;
     kv = PyUnicode_FromString(key);
-    if (kv == NULL) {
+    if (kv == nullptr) {
         throw error_already_set();
     }
 
     rv = PyDict_GetItemWithError(v, kv);
     Py_DECREF(kv);
-    if (rv == NULL && PyErr_Occurred()) {
+    if (rv == nullptr && PyErr_Occurred()) {
         throw error_already_set();
     }
     return rv;
@@ -614,7 +614,7 @@ inline PyObject *dict_getitemstring(PyObject *v, const char *key) {
 
 inline PyObject *dict_getitem(PyObject *v, PyObject *key) {
     PyObject *rv = PyDict_GetItemWithError(v, key);
-    if (rv == NULL && PyErr_Occurred()) {
+    if (rv == nullptr && PyErr_Occurred()) {
         throw error_already_set();
     }
     return rv;
@@ -1914,8 +1914,8 @@ public:
         return memoryview::from_buffer(reinterpret_cast<void *>(ptr),
                                        sizeof(T),
                                        format_descriptor<T>::value,
-                                       shape,
+                                       std::move(shape),
-                                       strides,
+                                       std::move(strides),
                                        readonly);
     }
 
@@ -1923,7 +1923,8 @@ public:
     static memoryview from_buffer(const T *ptr,
                                   detail::any_container<ssize_t> shape,
                                   detail::any_container<ssize_t> strides) {
-        return memoryview::from_buffer(const_cast<T *>(ptr), shape, strides, true);
+        return memoryview::from_buffer(
+            const_cast<T *>(ptr), std::move(shape), std::move(strides), true);
     }
 
     /** \rst

setup.cfg

@@ -46,4 +46,4 @@ max-line-length = 120
 show_source = True
 exclude = .git, __pycache__, build, dist, docs, tools, venv
 extend-ignore = E203, E722, B950
-select = C,E,F,N,W,B,B9
+extend-select = B9

tests/cross_module_gil_utils.cpp

@@ -25,8 +25,8 @@ void gil_acquire() { py::gil_scoped_acquire gil; }
 
 constexpr char kModuleName[] = "cross_module_gil_utils";
 
-struct PyModuleDef moduledef
+struct PyModuleDef moduledef = {
-    = {PyModuleDef_HEAD_INIT, kModuleName, NULL, 0, NULL, NULL, NULL, NULL, NULL};
+    PyModuleDef_HEAD_INIT, kModuleName, nullptr, 0, nullptr, nullptr, nullptr, nullptr, nullptr};
 
 } // namespace
 
@@ -34,7 +34,7 @@ extern "C" PYBIND11_EXPORT PyObject *PyInit_cross_module_gil_utils() {
 
     PyObject *m = PyModule_Create(&moduledef);
 
-    if (m != NULL) {
+    if (m != nullptr) {
         static_assert(sizeof(&gil_acquire) == sizeof(void *),
                       "Function pointer must have the same size as void*");
         PyModule_AddObject(

tests/pybind11_tests.cpp

@@ -67,10 +67,10 @@ PYBIND11_MODULE(pybind11_tests, m) {
 
     bind_ConstructorStats(m);
 
-#if !defined(NDEBUG)
+#if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
-    m.attr("debug_enabled") = true;
+    m.attr("detailed_error_messages_enabled") = true;
 #else
-    m.attr("debug_enabled") = false;
+    m.attr("detailed_error_messages_enabled") = false;
 #endif
 
     py::class_<UserType>(m, "UserType", "A `py::class_` type for testing")

tests/test_methods_and_attributes.cpp

@@ -361,10 +361,10 @@ TEST_SUBMODULE(methods_and_attributes, m) {
 
     // test_bad_arg_default
     // Issue/PR #648: bad arg default debugging output
-#if !defined(NDEBUG)
+#if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
-    m.attr("debug_enabled") = true;
+    m.attr("detailed_error_messages_enabled") = true;
 #else
-    m.attr("debug_enabled") = false;
+    m.attr("detailed_error_messages_enabled") = false;
 #endif
     m.def("bad_arg_def_named", [] {
         auto m = py::module_::import("pybind11_tests");

tests/test_methods_and_attributes.py

@@ -216,15 +216,15 @@ def test_metaclass_override():
 
 
 def test_no_mixed_overloads():
-    from pybind11_tests import debug_enabled
+    from pybind11_tests import detailed_error_messages_enabled
 
     with pytest.raises(RuntimeError) as excinfo:
         m.ExampleMandA.add_mixed_overloads1()
     assert str(
         excinfo.value
     ) == "overloading a method with both static and instance methods is not supported; " + (
-        "compile in debug mode for more details"
+        "#define PYBIND11_DETAILED_ERROR_MESSAGES or compile in debug mode for more details"
-        if not debug_enabled
+        if not detailed_error_messages_enabled
         else "error while attempting to bind static method ExampleMandA.overload_mixed1"
         "(arg0: float) -> str"
     )
@@ -234,8 +234,8 @@ def test_no_mixed_overloads():
     assert str(
         excinfo.value
     ) == "overloading a method with both static and instance methods is not supported; " + (
-        "compile in debug mode for more details"
+        "#define PYBIND11_DETAILED_ERROR_MESSAGES or compile in debug mode for more details"
-        if not debug_enabled
+        if not detailed_error_messages_enabled
         else "error while attempting to bind instance method ExampleMandA.overload_mixed2"
         "(self: pybind11_tests.methods_and_attributes.ExampleMandA, arg0: int, arg1: int)"
         " -> str"
@@ -344,16 +344,16 @@ def test_cyclic_gc():
 
 
 def test_bad_arg_default(msg):
-    from pybind11_tests import debug_enabled
+    from pybind11_tests import detailed_error_messages_enabled
 
     with pytest.raises(RuntimeError) as excinfo:
         m.bad_arg_def_named()
     assert msg(excinfo.value) == (
         "arg(): could not convert default argument 'a: UnregisteredType' in function "
         "'should_fail' into a Python object (type not registered yet?)"
-        if debug_enabled
+        if detailed_error_messages_enabled
         else "arg(): could not convert default argument into a Python object (type not registered "
-        "yet?). Compile in debug mode for more information."
+        "yet?). #define PYBIND11_DETAILED_ERROR_MESSAGES or compile in debug mode for more information."
     )
 
     with pytest.raises(RuntimeError) as excinfo:
@@ -361,9 +361,9 @@ def test_bad_arg_default(msg):
     assert msg(excinfo.value) == (
         "arg(): could not convert default argument 'UnregisteredType' in function "
         "'should_fail' into a Python object (type not registered yet?)"
-        if debug_enabled
+        if detailed_error_messages_enabled
         else "arg(): could not convert default argument into a Python object (type not registered "
-        "yet?). Compile in debug mode for more information."
+        "yet?). #define PYBIND11_DETAILED_ERROR_MESSAGES or compile in debug mode for more information."
     )
 
 

tests/test_numpy_dtypes.cpp

@@ -289,8 +289,8 @@ py::list test_dtype_ctors() {
     dict["itemsize"] = py::int_(20);
     list.append(py::dtype::from_args(dict));
     list.append(py::dtype(names, formats, offsets, 20));
-    list.append(py::dtype(py::buffer_info((void *) 0, sizeof(unsigned int), "I", 1)));
+    list.append(py::dtype(py::buffer_info((void *) nullptr, sizeof(unsigned int), "I", 1)));
-    list.append(py::dtype(py::buffer_info((void *) 0, 0, "T{i:a:f:b:}", 1)));
+    list.append(py::dtype(py::buffer_info((void *) nullptr, 0, "T{i:a:f:b:}", 1)));
     list.append(py::dtype(py::detail::npy_api::NPY_DOUBLE_));
     return list;
 }
@@ -610,5 +610,5 @@ TEST_SUBMODULE(numpy_dtypes, m) {
           []() { PYBIND11_NUMPY_DTYPE(SimpleStruct, bool_, uint_, float_, ldbl_); });
 
     // test_str_leak
-    m.def("dtype_wrapper", [](py::object d) { return py::dtype::from_args(std::move(d)); });
+    m.def("dtype_wrapper", [](const py::object &d) { return py::dtype::from_args(d); });
 }

tests/test_pickling.cpp

@@ -61,6 +61,8 @@ void wrap(py::module m) {
 } // namespace exercise_trampoline
 
 TEST_SUBMODULE(pickling, m) {
+    m.def("simple_callable", []() { return 20220426; });
+
     // test_roundtrip
     class Pickleable {
     public:

tests/test_pickling.py

@@ -1,4 +1,5 @@
 import pickle
+import re
 
 import pytest
 
@@ -6,6 +7,20 @@ import env
 from pybind11_tests import pickling as m
 
 
+def test_pickle_simple_callable():
+    assert m.simple_callable() == 20220426
+    if env.PYPY:
+        serialized = pickle.dumps(m.simple_callable)
+        deserialized = pickle.loads(serialized)
+        assert deserialized() == 20220426
+    else:
+        # To document broken behavior: currently it fails universally with
+        # all C Python versions.
+        with pytest.raises(TypeError) as excinfo:
+            pickle.dumps(m.simple_callable)
+        assert re.search("can.*t pickle .*PyCapsule.* object", str(excinfo.value))
+
+
 @pytest.mark.parametrize("cls_name", ["Pickleable", "PickleableNew"])
 def test_roundtrip(cls_name):
     cls = getattr(m, cls_name)

tests/test_pytypes.py

@@ -4,7 +4,7 @@ import sys
 import pytest
 
 import env
-from pybind11_tests import debug_enabled
+from pybind11_tests import detailed_error_messages_enabled
 from pybind11_tests import pytypes as m
 
 
@@ -416,8 +416,8 @@ def test_print(capture):
         m.print_failure()
     assert str(excinfo.value) == "Unable to convert call argument " + (
         "'1' of type 'UnregisteredType' to Python object"
-        if debug_enabled
+        if detailed_error_messages_enabled
-        else "to Python object (compile in debug mode for details)"
+        else "to Python object (#define PYBIND11_DETAILED_ERROR_MESSAGES or compile in debug mode for details)"
     )
 
 

tests/test_stl.py

@@ -14,6 +14,7 @@ def test_vector(doc):
 
     assert m.cast_bool_vector() == [True, False]
     assert m.load_bool_vector([True, False])
+    assert m.load_bool_vector(tuple([True, False]))
 
     assert doc(m.cast_vector) == "cast_vector() -> List[int]"
     assert doc(m.load_vector) == "load_vector(arg0: List[int]) -> bool"
@@ -36,6 +37,7 @@ def test_array(doc):
     lst = m.cast_array()
     assert lst == [1, 2]
     assert m.load_array(lst)
+    assert m.load_array(tuple(lst))
 
     assert doc(m.cast_array) == "cast_array() -> List[int[2]]"
     assert doc(m.load_array) == "load_array(arg0: List[int[2]]) -> bool"
@@ -46,6 +48,7 @@ def test_valarray(doc):
     lst = m.cast_valarray()
     assert lst == [1, 4, 9]
     assert m.load_valarray(lst)
+    assert m.load_valarray(tuple(lst))
 
     assert doc(m.cast_valarray) == "cast_valarray() -> List[int]"
     assert doc(m.load_valarray) == "load_valarray(arg0: List[int]) -> bool"