Final manual curation in preparation for global clang-formating (#3712)

* Manual line breaks to pre-empt undesired `clang-format`ing.

Informed by work under https://github.com/pybind/pybind11/pull/3683:

60b7eb410f

59572e6559

* Manual curation of clang-format diffs involving source code comments.

Very labor-intensive and dull.

* Pulling .clang-format change from @henryiii's 9057962d40

* Adding commonly used .clang-format `CommentPragmas:`

* Ensure short lambdas are allowed

Co-authored-by: Aaron Gokaslan <skylion.aaron@gmail.com>

.clang-format

@@ -3,17 +3,36 @@
 # clang-format --style=llvm --dump-config
 BasedOnStyle: LLVM
 AccessModifierOffset: -4
+AllowShortLambdasOnASingleLine: true
 AlwaysBreakTemplateDeclarations: Yes
 BinPackArguments: false
 BinPackParameters: false
 BreakBeforeBinaryOperators: All
 BreakConstructorInitializers: BeforeColon
 ColumnLimit: 99
+CommentPragmas: 'NOLINT:.*|^ IWYU pragma:'
+IncludeBlocks: Regroup
 IndentCaseLabels: true
 IndentPPDirectives: AfterHash
 IndentWidth: 4
 Language: Cpp
 SpaceAfterCStyleCast: true
 Standard: Cpp11
+StatementMacros: ['PyObject_HEAD']
 TabWidth: 4
+IncludeCategories:
+  - Regex:           '<pybind11/.*'
+    Priority:        -1
+  - Regex:           'pybind11.h"$'
+    Priority:        1
+  - Regex:           '^".*/?detail/'
+    Priority:        1
+    SortPriority:    2
+  - Regex:           '^"'
+    Priority:        1
+    SortPriority:    3
+  - Regex:           '<[[:alnum:]._]+>'
+    Priority:        4
+  - Regex:           '.*'
+    Priority:        5
 ...

include/pybind11/buffer_info.h

@@ -44,10 +44,12 @@ struct buffer_info {
     void *ptr = nullptr;          // Pointer to the underlying storage
     ssize_t itemsize = 0;         // Size of individual items in bytes
     ssize_t size = 0;             // Total number of entries
-    std::string format;           // For homogeneous buffers, this should be set to format_descriptor<T>::format()
+    std::string format; // For homogeneous buffers, this should be set to
+                        // format_descriptor<T>::format()
     ssize_t ndim = 0;             // Number of dimensions
     std::vector<ssize_t> shape;   // Shape of the tensor (1 entry per dimension)
-    std::vector<ssize_t> strides; // Number of bytes between adjacent entries (for each per dimension)
+    std::vector<ssize_t> strides; // Number of bytes between adjacent entries
+                                  // (for each per dimension)
     bool readonly = false;        // flag to indicate if the underlying storage may be written to
 
     buffer_info() = default;

include/pybind11/cast.h

@@ -996,7 +996,9 @@ PYBIND11_NAMESPACE_BEGIN(detail)
 template <typename T, enable_if_t<!is_pyobject<T>::value, int>>
 object object_or_cast(T &&o) { return pybind11::cast(std::forward<T>(o)); }
 
-struct override_unused {}; // Placeholder type for the unneeded (and dead code) static variable in the PYBIND11_OVERRIDE_OVERRIDE macro
+// Placeholder type for the unneeded (and dead code) static variable in the
+// PYBIND11_OVERRIDE_OVERRIDE macro
+struct override_unused {};
 template <typename ret_type> using override_caster_t = conditional_t<
     cast_is_temporary_value_reference<ret_type>::value, make_caster<ret_type>, override_unused>;
 
@@ -1463,7 +1465,8 @@ handle type::handle_of() {
     }}
 
 /// Lets you pass a type containing a `,` through a macro parameter without needing a separate
-/// typedef, e.g.: `PYBIND11_OVERRIDE(PYBIND11_TYPE(ReturnType<A, B>), PYBIND11_TYPE(Parent<C, D>), f, arg)`
+/// typedef, e.g.:
+/// `PYBIND11_OVERRIDE(PYBIND11_TYPE(ReturnType<A, B>), PYBIND11_TYPE(Parent<C, D>), f, arg)`
 #define PYBIND11_TYPE(...) __VA_ARGS__
 
 PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

include/pybind11/chrono.h

@@ -38,7 +38,8 @@ public:
     using rep = typename type::rep;
     using period = typename type::period;
 
-    using days = std::chrono::duration<int_least32_t, std::ratio<86400>>; // signed 25 bits required by the standard.
+    // signed 25 bits required by the standard.
+    using days = std::chrono::duration<int_least32_t, std::ratio<86400>>;
 
     bool load(handle src, bool) {
         using namespace std::chrono;

include/pybind11/detail/common.h

@@ -42,8 +42,9 @@
 #    endif
 #  endif
 #elif defined(_MSC_VER) && __cplusplus == 199711L
-// MSVC sets _MSVC_LANG rather than __cplusplus (supposedly until the standard is fully implemented)
+// MSVC sets _MSVC_LANG rather than __cplusplus (supposedly until the standard is fully
-// Unless you use the /Zc:__cplusplus flag on Visual Studio 2017 15.7 Preview 3 or newer
+// implemented). Unless you use the /Zc:__cplusplus flag on Visual Studio 2017 15.7 Preview 3
+// or newer.
 #  if _MSVC_LANG >= 201402L
 #    define PYBIND11_CPP14
 #    if _MSVC_LANG > 201402L && _MSC_VER >= 1910
@@ -722,8 +723,8 @@ template <typename T, typename... Ts>
 constexpr int last(int i, int result, T v, Ts... vs) { return last(i + 1, v ? i : result, vs...); }
 PYBIND11_NAMESPACE_END(constexpr_impl)
 
-/// Return the index of the first type in Ts which satisfies Predicate<T>.  Returns sizeof...(Ts) if
+/// Return the index of the first type in Ts which satisfies Predicate<T>.
-/// none match.
+/// Returns sizeof...(Ts) if none match.
 template <template<typename> class Predicate, typename... Ts>
 constexpr int constexpr_first() { return constexpr_impl::first(0, Predicate<Ts>::value...); }
 
@@ -842,7 +843,9 @@ PYBIND11_NAMESPACE_END(detail)
 
 #if defined(_MSC_VER)
 #  pragma warning(push)
-#  pragma warning(disable: 4275) // warning C4275: An exported class was derived from a class that wasn't exported. Can be ignored when derived from a STL class.
+#  pragma warning(disable: 4275)
+//     warning C4275: An exported class was derived from a class that wasn't exported.
+//     Can be ignored when derived from a STL class.
 #endif
 /// C++ bindings of builtin Python exceptions
 class PYBIND11_EXPORT_EXCEPTION builtin_exception : public std::runtime_error {
@@ -870,7 +873,9 @@ PYBIND11_RUNTIME_EXCEPTION(type_error, PyExc_TypeError)
 PYBIND11_RUNTIME_EXCEPTION(buffer_error, PyExc_BufferError)
 PYBIND11_RUNTIME_EXCEPTION(import_error, PyExc_ImportError)
 PYBIND11_RUNTIME_EXCEPTION(attribute_error, PyExc_AttributeError)
-PYBIND11_RUNTIME_EXCEPTION(cast_error, PyExc_RuntimeError) /// Thrown when pybind11::cast or handle::call fail due to a type casting error
+PYBIND11_RUNTIME_EXCEPTION(cast_error, PyExc_RuntimeError) /// Thrown when pybind11::cast or
+                                                           /// handle::call fail due to a type
+                                                           /// casting error
 PYBIND11_RUNTIME_EXCEPTION(reference_cast_error, PyExc_RuntimeError) /// Used internally
 
 [[noreturn]] PYBIND11_NOINLINE void pybind11_fail(const char *reason) { throw std::runtime_error(reason); }
@@ -974,13 +979,14 @@ public:
     template <typename It, typename = enable_if_t<is_input_iterator<It>::value>>
     any_container(It first, It last) : v(first, last) { }
 
-    // Implicit conversion constructor from any arbitrary container type with values convertible to T
+    // Implicit conversion constructor from any arbitrary container type
+    // with values convertible to T
     template <typename Container, typename = enable_if_t<std::is_convertible<decltype(*std::begin(std::declval<const Container &>())), T>::value>>
     // NOLINTNEXTLINE(google-explicit-constructor)
     any_container(const Container &c) : any_container(std::begin(c), std::end(c)) { }
 
-    // initializer_list's aren't deducible, so don't get matched by the above template; we need this
+    // initializer_list's aren't deducible, so don't get matched by the above template;
-    // to explicitly allow implicit conversion from one:
+    // we need this to explicitly allow implicit conversion from one:
     template <typename TIn, typename = enable_if_t<std::is_convertible<TIn, T>::value>>
     any_container(const std::initializer_list<TIn> &c) : any_container(c.begin(), c.end()) { }
 

include/pybind11/detail/internals.h

@@ -147,18 +147,22 @@ struct override_hash {
 /// Whenever binary incompatible changes are made to this structure,
 /// `PYBIND11_INTERNALS_VERSION` must be incremented.
 struct internals {
-    type_map<type_info *> registered_types_cpp; // std::type_index -> pybind11's type information
+    // std::type_index -> pybind11's type information
-    std::unordered_map<PyTypeObject *, std::vector<type_info *>> registered_types_py; // PyTypeObject* -> base type_info(s)
+    type_map<type_info *> registered_types_cpp;
+    // PyTypeObject* -> base type_info(s)
+    std::unordered_map<PyTypeObject *, std::vector<type_info *>> registered_types_py;
     std::unordered_multimap<const void *, instance*> registered_instances; // void * -> instance*
     std::unordered_set<std::pair<const PyObject *, const char *>, override_hash> inactive_override_cache;
     type_map<std::vector<bool (*)(PyObject *, void *&)>> direct_conversions;
     std::unordered_map<const PyObject *, std::vector<PyObject *>> patients;
     std::forward_list<ExceptionTranslator> registered_exception_translators;
-    std::unordered_map<std::string, void *> shared_data; // Custom data to be shared across extensions
+    std::unordered_map<std::string, void *> shared_data; // Custom data to be shared across
+                                                         // extensions
 #if PYBIND11_INTERNALS_VERSION == 4
     std::vector<PyObject *> unused_loader_patient_stack_remove_at_v5;
 #endif
-    std::forward_list<std::string> static_strings; // Stores the std::strings backing detail::c_str()
+    std::forward_list<std::string> static_strings; // Stores the std::strings backing
+                                                   // detail::c_str()
     PyTypeObject *static_property_type;
     PyTypeObject *default_metaclass;
     PyObject *instance_base;

include/pybind11/detail/type_caster_base.h

@@ -426,7 +426,8 @@ PYBIND11_NOINLINE void instance::allocate_layout() {
             space += t->holder_size_in_ptrs; // holder instance
         }
         size_t flags_at = space;
-        space += size_in_ptrs(n_types); // status bytes (holder_constructed and instance_registered)
+        space += size_in_ptrs(n_types); // status bytes (holder_constructed and
+                                        // instance_registered)
 
         // Allocate space for flags, values, and holders, and initialize it to 0 (flags and values,
         // in particular, need to be 0).  Use Python's memory allocation functions: in Python 3.6

include/pybind11/iostream.h

@@ -164,7 +164,8 @@ PYBIND11_NAMESPACE_END(detail)
     .. code-block:: cpp
 
         {
-            py::scoped_ostream_redirect output{std::cerr, py::module::import("sys").attr("stderr")};
+            py::scoped_ostream_redirect output{
+                std::cerr, py::module::import("sys").attr("stderr")};
             std::cout << "Hello, World!";
         }
  \endrst */

include/pybind11/numpy.h

@@ -325,7 +325,8 @@ template <typename T, size_t N> struct array_info<T[N]> : array_info<std::array<
 template <typename T> using remove_all_extents_t = typename array_info<T>::type;
 
 template <typename T> using is_pod_struct = all_of<
-    std::is_standard_layout<T>,     // since we're accessing directly in memory we need a standard layout type
+    std::is_standard_layout<T>,     // since we're accessing directly in memory
+                                    // we need a standard layout type
 #if defined(__GLIBCXX__) && (__GLIBCXX__ < 20150422 || __GLIBCXX__ == 20150426 || __GLIBCXX__ == 20150623 || __GLIBCXX__ == 20150626 || __GLIBCXX__ == 20160803)
     // libstdc++ < 5 (including versions 4.8.5, 4.9.3 and 4.9.4 which were released after 5)
     // don't implement is_trivially_copyable, so approximate it

include/pybind11/options.h

@@ -51,7 +51,8 @@ private:
 
     struct state {
         bool show_user_defined_docstrings = true;  //< Include user-supplied texts in docstrings.
-        bool show_function_signatures = true;      //< Include auto-generated function signatures in docstrings.
+        bool show_function_signatures = true;      //< Include auto-generated function signatures
+                                                   //  in docstrings.
     };
 
     static state &global_state() {

include/pybind11/pybind11.h

@@ -242,7 +242,8 @@ protected:
 
         rec->nargs_pos = cast_in::args_pos >= 0
             ? static_cast<std::uint16_t>(cast_in::args_pos)
-            : sizeof...(Args) - cast_in::has_kwargs; // Will get reduced more if we have a kw_only
+            : sizeof...(Args) - cast_in::has_kwargs; // Will get reduced more if
+                                                     // we have a kw_only
         rec->has_args = cast_in::args_pos >= 0;
         rec->has_kwargs = cast_in::has_kwargs;
 
@@ -263,7 +264,8 @@ protected:
             static_assert(!(has_kw_only_args && has_pos_only_args) || pos_only_pos < kw_only_pos, "py::pos_only must come before py::kw_only");
         }
 
-        /* Generate a readable signature describing the function's arguments and return value types */
+        /* Generate a readable signature describing the function's arguments and return
+           value types */
         static constexpr auto signature = const_name("(") + cast_in::arg_names + const_name(") -> ") + cast_out::name;
         PYBIND11_DESCR_CONSTEXPR auto types = decltype(signature)::types();
 
@@ -400,7 +402,8 @@ protected:
                     handle th((PyObject *) tinfo->type);
                     signature +=
                         th.attr("__module__").cast<std::string>() + "." +
-                        th.attr("__qualname__").cast<std::string>(); // Python 3.3+, but we backport it to earlier versions
+                        // Python 3.3+, but we backport it to earlier versions
+                        th.attr("__qualname__").cast<std::string>();
                 } else if (rec->is_new_style_constructor && arg_index == 0) {
                     // A new-style `__init__` takes `self` as `value_and_holder`.
                     // Rewrite it to the proper class type.
@@ -639,7 +642,8 @@ protected:
         const function_record *overloads = (function_record *) PyCapsule_GetPointer(self, nullptr),
                               *it = overloads;
 
-        /* Need to know how many arguments + keyword arguments there are to pick the right overload */
+        /* Need to know how many arguments + keyword arguments there are to pick the right
+           overload */
         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,
@@ -715,7 +719,8 @@ protected:
 
                 function_call call(func, parent);
 
-                size_t args_to_copy = (std::min)(pos_args, n_args_in); // Protect std::min with parentheses
+                // Protect std::min with parentheses
+                size_t args_to_copy = (std::min)(pos_args, n_args_in);
                 size_t args_copied = 0;
 
                 // 0. Inject new-style `self` argument
@@ -956,7 +961,8 @@ protected:
                 - catch the exception and call PyErr_SetString or PyErr_SetObject
                   to set a standard (or custom) Python exception, or
                 - do nothing and let the exception fall through to the next translator, or
-                - delegate translation to the next translator by throwing a new type of exception. */
+                - delegate translation to the next translator by throwing a new type of exception.
+             */
 
             auto &local_exception_translators = get_local_internals().registered_exception_translators;
             if (detail::apply_exception_translators(local_exception_translators)) {
@@ -1169,8 +1175,8 @@ public:
         Adds an object to the module using the given name.  Throws if an object with the given name
         already exists.
 
-        ``overwrite`` should almost always be false: attempting to overwrite objects that pybind11 has
+        ``overwrite`` should almost always be false: attempting to overwrite objects that pybind11
-        established will, in most cases, break things.
+        has established will, in most cases, break things.
     \endrst */
     PYBIND11_NOINLINE void add_object(const char *name, handle obj, bool overwrite = false) {
         if (!overwrite && hasattr(*this, name)) {
@@ -1197,7 +1203,8 @@ public:
     static module_ create_extension_module(const char *name, const char *doc, module_def *def) {
 #if PY_MAJOR_VERSION >= 3
         // module_def is PyModuleDef
-        def = new (def) PyModuleDef {  // Placement new (not an allocation).
+        // Placement new (not an allocation).
+        def = new (def) PyModuleDef {
             /* m_base */     PyModuleDef_HEAD_INIT,
             /* m_name */     name,
             /* m_doc */      options::show_user_defined_docstrings() ? doc : nullptr,
@@ -1456,7 +1463,8 @@ public:
             none_of<is_pyobject<Extra>...>::value || // no base class arguments, or:
             (   constexpr_sum(is_pyobject<Extra>::value...) == 1 && // Exactly one base
                 constexpr_sum(is_base<options>::value...)   == 0 && // no template option bases
-                none_of<std::is_same<multiple_inheritance, Extra>...>::value), // no multiple_inheritance attr
+                // no multiple_inheritance attr
+                none_of<std::is_same<multiple_inheritance, Extra>...>::value),
             "Error: multiple inheritance bases must be specified via class_ template options");
 
         type_record record;
@@ -2562,10 +2570,11 @@ inline function get_type_override(const void *this_ptr, const type_info *this_ty
 PYBIND11_NAMESPACE_END(detail)
 
 /** \rst
-  Try to retrieve a python method by the provided name from the instance pointed to by the this_ptr.
+  Try to retrieve a python method by the provided name from the instance pointed to by the
+  this_ptr.
 
-  :this_ptr: The pointer to the object the overridden method should be retrieved for. This should be
+  :this_ptr: The pointer to the object the overridden method should be retrieved for. This should
-             the first non-trampoline class encountered in the inheritance chain.
+             be the first non-trampoline class encountered in the inheritance chain.
   :name: The name of the overridden Python method to retrieve.
   :return: The Python method by this name from the object or an empty function wrapper.
  \endrst */
@@ -2590,9 +2599,10 @@ template <class T> function get_override(const T *this_ptr, const char *name) {
     } while (false)
 
 /** \rst
-    Macro to populate the virtual method in the trampoline class. This macro tries to look up a method named 'fn'
+    Macro to populate the virtual method in the trampoline class. This macro tries to look up a
-    from the Python side, deals with the :ref:`gil` and necessary argument conversions to call this method and return
+    method named 'fn' from the Python side, deals with the :ref:`gil` and necessary argument
-    the appropriate type. See :ref:`overriding_virtuals` for more information. This macro should be used when the method
+    conversions to call this method and return the appropriate type.
+    See :ref:`overriding_virtuals` for more information. This macro should be used when the method
     name in C is not the same as the method name in Python. For example with `__str__`.
 
     .. code-block:: cpp
@@ -2613,8 +2623,8 @@ template <class T> function get_override(const T *this_ptr, const char *name) {
     } while (false)
 
 /** \rst
-    Macro for pure virtual functions, this function is identical to :c:macro:`PYBIND11_OVERRIDE_NAME`, except that it
+    Macro for pure virtual functions, this function is identical to
-    throws if no override can be found.
+    :c:macro:`PYBIND11_OVERRIDE_NAME`, except that it throws if no override can be found.
 \endrst */
 #define PYBIND11_OVERRIDE_PURE_NAME(ret_type, cname, name, fn, ...) \
     do { \
@@ -2623,9 +2633,10 @@ template <class T> function get_override(const T *this_ptr, const char *name) {
     } while (false)
 
 /** \rst
-    Macro to populate the virtual method in the trampoline class. This macro tries to look up the method
+    Macro to populate the virtual method in the trampoline class. This macro tries to look up the
-    from the Python side, deals with the :ref:`gil` and necessary argument conversions to call this method and return
+    method from the Python side, deals with the :ref:`gil` and necessary argument conversions to
-    the appropriate type. This macro should be used if the method name in C and in Python are identical.
+    call this method and return the appropriate type. This macro should be used if the method name
+    in C and in Python are identical.
     See :ref:`overriding_virtuals` for more information.
 
     .. code-block:: cpp
@@ -2650,8 +2661,8 @@ template <class T> function get_override(const T *this_ptr, const char *name) {
     PYBIND11_OVERRIDE_NAME(PYBIND11_TYPE(ret_type), PYBIND11_TYPE(cname), #fn, fn, __VA_ARGS__)
 
 /** \rst
-    Macro for pure virtual functions, this function is identical to :c:macro:`PYBIND11_OVERRIDE`, except that it throws
+    Macro for pure virtual functions, this function is identical to :c:macro:`PYBIND11_OVERRIDE`,
-    if no override can be found.
+    except that it throws if no override can be found.
 \endrst */
 #define PYBIND11_OVERRIDE_PURE(ret_type, cname, fn, ...) \
     PYBIND11_OVERRIDE_PURE_NAME(PYBIND11_TYPE(ret_type), PYBIND11_TYPE(cname), #fn, fn, __VA_ARGS__)

include/pybind11/pytypes.h

@@ -161,7 +161,8 @@ public:
     /// Return the object's current reference count
     int ref_count() const { return static_cast<int>(Py_REFCNT(derived().ptr())); }
 
-    // TODO PYBIND11_DEPRECATED("Call py::type::handle_of(h) or py::type::of(h) instead of h.get_type()")
+    // TODO PYBIND11_DEPRECATED(
+    //     "Call py::type::handle_of(h) or py::type::of(h) instead of h.get_type()")
     handle get_type() const;
 
 private:
@@ -337,7 +338,9 @@ PYBIND11_NAMESPACE_END(detail)
 
 #if defined(_MSC_VER)
 #  pragma warning(push)
-#  pragma warning(disable: 4275 4251) // warning C4275: An exported class was derived from a class that wasn't exported. Can be ignored when derived from a STL class.
+#  pragma warning(disable: 4275 4251)
+//     warning C4275: An exported class was derived from a class that wasn't exported.
+//     Can be ignored when derived from a STL class.
 #endif
 /// Fetch and hold an error which was already set in Python.  An instance of this is typically
 /// thrown to propagate python-side errors back through C++ which can either be caught manually or
@@ -1745,7 +1748,8 @@ public:
 
         See also: Python C API documentation for `PyMemoryView_FromBuffer`_.
 
-        .. _PyMemoryView_FromBuffer: https://docs.python.org/c-api/memoryview.html#c.PyMemoryView_FromBuffer
+        .. _PyMemoryView_FromBuffer:
+           https://docs.python.org/c-api/memoryview.html#c.PyMemoryView_FromBuffer
 
         :param ptr: Pointer to the buffer.
         :param itemsize: Byte size of an element.
@@ -1800,7 +1804,8 @@ public:
 
         See also: Python C API documentation for `PyMemoryView_FromBuffer`_.
 
-        .. _PyMemoryView_FromMemory: https://docs.python.org/c-api/memoryview.html#c.PyMemoryView_FromMemory
+        .. _PyMemoryView_FromMemory:
+           https://docs.python.org/c-api/memoryview.html#c.PyMemoryView_FromMemory
      \endrst */
     static memoryview from_memory(void *mem, ssize_t size, bool readonly = false) {
         PyObject* ptr = PyMemoryView_FromMemory(

include/pybind11/stl_bind.h

@@ -44,7 +44,8 @@ struct is_comparable<
                    container_traits<T>::is_comparable>>
     : std::true_type { };
 
-/* For a vector/map data structure, recursively check the value type (which is std::pair for maps) */
+/* For a vector/map data structure, recursively check the value type
+   (which is std::pair for maps) */
 template <typename T>
 struct is_comparable<T, enable_if_t<container_traits<T>::is_vector>> {
     static constexpr const bool value =
@@ -384,7 +385,8 @@ template <typename Vector, typename Class_> auto vector_if_insertion_operator(Cl
 }
 
 // Provide the buffer interface for vectors if we have data() and we have a format for it
-// GCC seems to have "void std::vector<bool>::data()" - doing SFINAE on the existence of data() is insufficient, we need to check it returns an appropriate pointer
+// GCC seems to have "void std::vector<bool>::data()" - doing SFINAE on the existence of data()
+// is insufficient, we need to check it returns an appropriate pointer
 template <typename Vector, typename = void>
 struct vector_has_data_and_format : std::false_type {};
 template <typename Vector>
@@ -408,7 +410,8 @@ void vector_buffer_impl(Class_& cl, std::true_type) {
 
     static_assert(vector_has_data_and_format<Vector>::value, "There is not an appropriate format descriptor for this vector");
 
-    // numpy.h declares this for arbitrary types, but it may raise an exception and crash hard at runtime if PYBIND11_NUMPY_DTYPE hasn't been called, so check here
+    // numpy.h declares this for arbitrary types, but it may raise an exception and crash hard
+    // at runtime if PYBIND11_NUMPY_DTYPE hasn't been called, so check here
     format_descriptor<T>::format();
 
     cl.def_buffer([](Vector& v) -> buffer_info {

tests/constructor_stats.h

@@ -72,8 +72,10 @@ inspection/testing in python) by using the functions with `print_` replaced with
 
 class ConstructorStats {
 protected:
-    std::unordered_map<void*, int> _instances; // Need a map rather than set because members can shared address with parents
+    std::unordered_map<void*, int> _instances; // Need a map rather than set because members can
-    std::list<std::string> _values; // Used to track values (e.g. of value constructors)
+                                               // shared address with parents
+    std::list<std::string> _values; // Used to track values
+                                    // (e.g. of value constructors)
 public:
     int default_constructions = 0;
     int copy_constructions = 0;

tests/pybind11_tests.h

@@ -5,8 +5,7 @@
 
 #if defined(_MSC_VER) && _MSC_VER < 1910
 // We get some really long type names here which causes MSVC 2015 to emit warnings
-#    pragma warning(                                                                              \
+#    pragma warning(disable : 4503) // NOLINT: warning C4503: decorated name length exceeded, name was truncated
-        disable : 4503) // warning C4503: decorated name length exceeded, name was truncated
 #endif
 
 namespace py = pybind11;

tests/test_class.cpp

@@ -22,7 +22,8 @@
 #include <utility>
 
 #if defined(_MSC_VER)
-#  pragma warning(disable: 4324) // warning C4324: structure was padded due to alignment specifier
+#  pragma warning(disable: 4324)
+//     warning C4324: structure was padded due to alignment specifier
 #endif
 
 // test_brace_initialization
@@ -534,22 +535,24 @@ CHECK_HOLDER(6, shared); CHECK_HOLDER(7, shared); CHECK_HOLDER(8, shared);
 #define CHECK_BROKEN(N) static_assert(std::is_same<typename Breaks##N::type, BreaksBase<-(N)>>::value, \
         "Breaks1 has wrong type!");
 
-//// Two holder classes:
+#ifdef PYBIND11_NEVER_DEFINED_EVER
-//typedef py::class_<BreaksBase<-1>, std::unique_ptr<BreaksBase<-1>>, std::unique_ptr<BreaksBase<-1>>> Breaks1;
+// Two holder classes:
-//CHECK_BROKEN(1);
+typedef py::class_<BreaksBase<-1>, std::unique_ptr<BreaksBase<-1>>, std::unique_ptr<BreaksBase<-1>>> Breaks1;
-//// Two aliases:
+CHECK_BROKEN(1);
-//typedef py::class_<BreaksBase<-2>, BreaksTramp<-2>, BreaksTramp<-2>> Breaks2;
+// Two aliases:
-//CHECK_BROKEN(2);
+typedef py::class_<BreaksBase<-2>, BreaksTramp<-2>, BreaksTramp<-2>> Breaks2;
-//// Holder + 2 aliases
+CHECK_BROKEN(2);
-//typedef py::class_<BreaksBase<-3>, std::unique_ptr<BreaksBase<-3>>, BreaksTramp<-3>, BreaksTramp<-3>> Breaks3;
+// Holder + 2 aliases
-//CHECK_BROKEN(3);
+typedef py::class_<BreaksBase<-3>, std::unique_ptr<BreaksBase<-3>>, BreaksTramp<-3>, BreaksTramp<-3>> Breaks3;
-//// Alias + 2 holders
+CHECK_BROKEN(3);
-//typedef py::class_<BreaksBase<-4>, std::unique_ptr<BreaksBase<-4>>, BreaksTramp<-4>, std::shared_ptr<BreaksBase<-4>>> Breaks4;
+// Alias + 2 holders
-//CHECK_BROKEN(4);
+typedef py::class_<BreaksBase<-4>, std::unique_ptr<BreaksBase<-4>>, BreaksTramp<-4>, std::shared_ptr<BreaksBase<-4>>> Breaks4;
-//// Invalid option (not a subclass or holder)
+CHECK_BROKEN(4);
-//typedef py::class_<BreaksBase<-5>, BreaksTramp<-4>> Breaks5;
+// Invalid option (not a subclass or holder)
-//CHECK_BROKEN(5);
+typedef py::class_<BreaksBase<-5>, BreaksTramp<-4>> Breaks5;
-//// Invalid option: multiple inheritance not supported:
+CHECK_BROKEN(5);
-//template <> struct BreaksBase<-8> : BreaksBase<-6>, BreaksBase<-7> {};
+// Invalid option: multiple inheritance not supported:
-//typedef py::class_<BreaksBase<-8>, BreaksBase<-6>, BreaksBase<-7>> Breaks8;
+template <> struct BreaksBase<-8> : BreaksBase<-6>, BreaksBase<-7> {};
-//CHECK_BROKEN(8);
+typedef py::class_<BreaksBase<-8>, BreaksBase<-6>, BreaksBase<-7>> Breaks8;
+CHECK_BROKEN(8);
+#endif

tests/test_kwargs_and_defaults.cpp

@@ -153,10 +153,12 @@ TEST_SUBMODULE(kwargs_and_defaults, m) {
 
 
     // These should fail to compile:
+#ifdef PYBIND11_NEVER_DEFINED_EVER
     // argument annotations are required when using kw_only
-//    m.def("bad_kw_only1", [](int) {}, py::kw_only());
+    m.def("bad_kw_only1", [](int) {}, py::kw_only());
     // can't specify both `py::kw_only` and a `py::args` argument
-//    m.def("bad_kw_only2", [](int i, py::args) {}, py::kw_only(), "i"_a);
+    m.def("bad_kw_only2", [](int i, py::args) {}, py::kw_only(), "i"_a);
+#endif
 
     // test_function_signatures (along with most of the above)
     struct KWClass { void foo(int, float) {} };

tests/test_modules.cpp

@@ -49,7 +49,8 @@ TEST_SUBMODULE(modules, m) {
         .def(py::init<>())
         .def("get_a1", &B::get_a1, "Return the internal A 1", py::return_value_policy::reference_internal)
         .def("get_a2", &B::get_a2, "Return the internal A 2", py::return_value_policy::reference_internal)
-        .def_readwrite("a1", &B::a1)  // def_readonly uses an internal reference return policy by default
+        .def_readwrite("a1", &B::a1)  // def_readonly uses an internal
+                                      // reference return policy by default
         .def_readwrite("a2", &B::a2);
 
     // This is intentionally "py::module" to verify it still can be used in place of "py::module_"

tests/test_numpy_array.cpp

@@ -399,7 +399,8 @@ TEST_SUBMODULE(numpy_array, sm) {
 
     // test_initializer_list
     // Issue (unnumbered; reported in #788): regression: initializer lists can be ambiguous
-    sm.def("array_initializer_list1", []() { return py::array_t<float>(1); }); // { 1 } also works, but clang warns about it
+    sm.def("array_initializer_list1", []() { return py::array_t<float>(1); });
+    // { 1 } also works for the above, but clang warns about it
     sm.def("array_initializer_list2", []() { return py::array_t<float>({ 1, 2 }); });
     sm.def("array_initializer_list3", []() { return py::array_t<float>({ 1, 2, 3 }); });
     sm.def("array_initializer_list4", []() { return py::array_t<float>({ 1, 2, 3, 4 }); });

tests/test_numpy_dtypes.cpp

@@ -308,10 +308,12 @@ TEST_SUBMODULE(numpy_dtypes, m) {
 
     PYBIND11_NUMPY_DTYPE_EX(StructWithUglyNames, __x__, "x", __y__, "y");
 
-    // If uncommented, this should produce a static_assert failure telling the user that the struct
+#ifdef PYBIND11_NEVER_DEFINED_EVER
+    // If enabled, this should produce a static_assert failure telling the user that the struct
     // is not a POD type
-//    struct NotPOD { std::string v; NotPOD() : v("hi") {}; };
+    struct NotPOD { std::string v; NotPOD() : v("hi") {}; };
-//    PYBIND11_NUMPY_DTYPE(NotPOD, v);
+    PYBIND11_NUMPY_DTYPE(NotPOD, v);
+#endif
 
     // Check that dtypes can be registered programmatically, both from
     // initializer lists of field descriptors and from other containers.

tests/test_virtual_functions.cpp

@@ -370,9 +370,12 @@ TEST_SUBMODULE(virtual_functions, m) {
     public:
         using OverrideTest::OverrideTest;
         std::string str_value() override { PYBIND11_OVERRIDE(std::string, OverrideTest, str_value); }
-        // Not allowed (uncommenting should hit a static_assert failure): we can't get a reference
+        // Not allowed (enabling the below should hit a static_assert failure): we can't get a
-        // to a python numeric value, since we only copy values in the numeric type caster:
+        // reference to a python numeric value, since we only copy values in the numeric type
-//      std::string &str_ref() override { PYBIND11_OVERRIDE(std::string &, OverrideTest, str_ref); }
+        // caster:
+#ifdef PYBIND11_NEVER_DEFINED_EVER
+        std::string &str_ref() override { PYBIND11_OVERRIDE(std::string &, OverrideTest, str_ref); }
+#endif
         // But we can work around it like this:
     private:
         std::string _tmp;
@@ -389,7 +392,9 @@ TEST_SUBMODULE(virtual_functions, m) {
     py::class_<OverrideTest, PyOverrideTest>(m, "OverrideTest")
         .def(py::init<const std::string &>())
         .def("str_value", &OverrideTest::str_value)
-//      .def("str_ref", &OverrideTest::str_ref)
+#ifdef PYBIND11_NEVER_DEFINED_EVER
+        .def("str_ref", &OverrideTest::str_ref)
+#endif
         .def("A_value", &OverrideTest::A_value)
         .def("A_ref", &OverrideTest::A_ref);
 
@@ -492,11 +497,11 @@ public:
 // Inheritance approach 2: templated trampoline classes.
 //
 // Advantages:
-// - we have only 2 (template) class and 4 method declarations (one per virtual method, plus one for
+// - we have only 2 (template) class and 4 method declarations (one per virtual method, plus one
-//   any override of a pure virtual method), versus 4 classes and 6 methods (MI) or 4 classes and 11
+//   for any override of a pure virtual method), versus 4 classes and 6 methods (MI) or 4 classes
-//   methods (repeat).
+//   and 11 methods (repeat).
-// - Compared to MI, we also don't have to change the non-trampoline inheritance to virtual, and can
+// - Compared to MI, we also don't have to change the non-trampoline inheritance to virtual, and
-//   properly inherit constructors.
+//   can properly inherit constructors.
 //
 // Disadvantage:
 // - the compiler must still generate and compile 14 different methods (more, even, than the 11
@@ -518,8 +523,8 @@ public:
     int unlucky_number() override { PYBIND11_OVERRIDE(int, Base, unlucky_number, ); }
     double lucky_number() override { PYBIND11_OVERRIDE(double, Base, lucky_number, ); }
 };
-// Since C_Tpl and D_Tpl don't declare any new virtual methods, we don't actually need these (we can
+// Since C_Tpl and D_Tpl don't declare any new virtual methods, we don't actually need these
-// use PyB_Tpl<C_Tpl> and PyB_Tpl<D_Tpl> for the trampoline classes instead):
+// (we can use PyB_Tpl<C_Tpl> and PyB_Tpl<D_Tpl> for the trampoline classes instead):
 /*
 template <class Base = C_Tpl> class PyC_Tpl : public PyB_Tpl<Base> {
 public: