docs: use more modern solution for Doxygen skipping

Author: henryiii

docs/Doxyfile

@@ -18,6 +18,5 @@ ALIASES               += "endrst=\endverbatim"
 QUIET                  = YES
 WARNINGS               = YES
 WARN_IF_UNDOCUMENTED   = NO
-PREDEFINED             = DOXYGEN_SHOULD_SKIP_THIS \
-                         PY_MAJOR_VERSION=3 \
+PREDEFINED             = PY_MAJOR_VERSION=3 \
                          PYBIND11_NOINLINE

docs/requirements.txt

@@ -1,8 +1,7 @@
-breathe==4.26.1
+breathe==4.31.0
 # docutils 0.17 breaks HTML tags & RTD theme
 # https://github.com/sphinx-doc/sphinx/issues/9001
-docutils==0.16
-sphinx==3.3.1
-sphinx_rtd_theme==0.5.0
-sphinxcontrib-moderncmakedomain==3.17
-sphinxcontrib-svg2pdfconverter==1.1.0
+sphinx==3.5.4
+sphinx_rtd_theme==1.0.0
+sphinxcontrib-moderncmakedomain==3.19
+sphinxcontrib-svg2pdfconverter==1.1.1

include/pybind11/pytypes.h

@@ -1,4 +1,4 @@
-/*
+nn/DOXY/*
     pybind11/pytypes.h: Convenience wrapper classes for basic Python types
 
     Copyright (c) 2016 Wenzel Jakob <[email protected]>
@@ -287,10 +287,10 @@ class object : public handle {
     struct borrowed_t { };
     struct stolen_t { };
 
-#ifndef DOXYGEN_SHOULD_SKIP_THIS  // Issue in breathe 4.26.1
+    /// @cond BROKEN
     template <typename T> friend T reinterpret_borrow(handle);
     template <typename T> friend T reinterpret_steal(handle);
-#endif
+    /// @endcond
 
 public:
     // Only accessible from derived classes and the reinterpret_* functions
@@ -1717,7 +1717,7 @@ class memoryview : public object {
 #endif
 };
 
-#ifndef DOXYGEN_SHOULD_SKIP_THIS
+/// @cond DUPLICATE
 inline memoryview memoryview::from_buffer(
     void *ptr, ssize_t itemsize, const char* format,
     detail::any_container<ssize_t> shape,
@@ -1745,7 +1745,7 @@ inline memoryview memoryview::from_buffer(
         throw error_already_set();
     return memoryview(object(obj, stolen_t{}));
 }
-#endif  // DOXYGEN_SHOULD_SKIP_THIS
+/// @endcond
 /// @} pytypes
 
 /// \addtogroup python_builtins