Features: Make CMAKE_CXX_KNOWN_FEATURES a property.

As a 'built-in' variable it imposes a cost on all variable lookups
and it is expected to be rarely used.

2 files changed, 2 insertions, 243 deletions

diff --git a/Help/variable/CMAKE_CXX_COMPILE_FEATURES.rst b/Help/variable/CMAKE_CXX_COMPILE_FEATURES.rst
index 6be0124..1102c21 100644
--- a/Help/variable/CMAKE_CXX_COMPILE_FEATURES.rst
+++ b/Help/variable/CMAKE_CXX_COMPILE_FEATURES.rst
@@ -4,5 +4,5 @@ CMAKE_CXX_COMPILE_FEATURES
 List of features known to the C++ compiler
 
 These features are known to be available for use with the C++ compiler. This
-list is a subset of the features listed in the :variable:`CMAKE_CXX_KNOWN_FEATURES`
-variable.
+list is a subset of the features listed in the :prop_gbl:`CMAKE_CXX_KNOWN_FEATURES`
+global property.
diff --git a/Help/variable/CMAKE_CXX_KNOWN_FEATURES.rst b/Help/variable/CMAKE_CXX_KNOWN_FEATURES.rst
deleted file mode 100644
index 7533f6d..0000000
--- a/Help/variable/CMAKE_CXX_KNOWN_FEATURES.rst
+++ /dev/null
@@ -1,241 +0,0 @@
-CMAKE_CXX_KNOWN_FEATURES
-------------------------
-
-List of C++ features known to this version of CMake.
-
-The features listed in this variable may be known to be available to the
-C++ compiler.  If the feature is available with the C++ compiler, it will
-be listed in the :variable:`CMAKE_CXX_COMPILE_FEATURES` variable.
-
-The features listed here may be used with the :command:`target_compile_features`
-command.
-
-The features known to this version of CMake are:
-
-``cxx_alias_templates``
-  Template aliases, as defined in N2258_.
-
-  .. _N2258: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2258.pdf
-
-``cxx_alignas``
-  Alignment control ``alignas``, as defined in N2341_.
-
-  .. _N2341: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2341.pdf
-
-``cxx_alignof``
-  Alignment control ``alignof``, as defined in N2341_.
-
-  .. _N2341: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2341.pdf
-
-``cxx_attributes``
-  Generic attributes, as defined in N2761_.
-
-  .. _N2761: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2761.pdf
-
-``cxx_auto_type``
-  Automatic type deduction, as defined in N1984_.
-
-  .. _N1984: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n1984.pdf
-
-``cxx_constexpr``
-  Constant expressions, as defined in N2235_.
-
-  .. _N2235: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2235.pdf
-
-``cxx_decltype_incomplete_return_types``
-  Decltype on incomplete return types, as defined in N3276_.
-
-  .. _N3276 : http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2011/n3276.pdf
-
-``cxx_decltype``
-  Decltype, as defined in N2343_.
-
-  .. _N2343: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2343.pdf
-
-``cxx_default_function_template_args``
-  Default template arguments for function templates, as defined in DR226_
-
-  .. _DR226: http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#226
-
-``cxx_defaulted_functions``
-  Defaulted functions, as defined in N2346_.
-
-  .. _N2346: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2346.htm
-
-``cxx_defaulted_move_initializers``
-  Defaulted move initializers, as defined in N3053_.
-
-  .. _N3053: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2010/n3053.html
-
-``cxx_delegating_constructors``
-  Delegating constructors, as defined in N1986_.
-
-  .. _N1986: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n1986.pdf
-
-``cxx_deleted_functions``
-  Deleted functions, as defined in  N2346_.
-
-  .. _N2346: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2346.htm
-
-``cxx_enum_forward_declarations``
-  Enum forward declarations, as defined in N2764_.
-
-  .. _N2764: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2764.pdf
-
-``cxx_explicit_conversions``
-  Explicit conversion operators, as defined in N2437_.
-
-  .. _N2437: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2437.pdf
-
-``cxx_extended_friend_declarations``
-  Extended friend declarations, as defined in N1791_.
-
-  .. _N1791: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1791.pdf
-
-``cxx_extern_templates``
-  Extern templates, as defined in N1987_.
-
-  .. _N1987: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n1987.htm
-
-``cxx_final``
-  Override control ``final`` keyword, as defined in N2928_.
-
-  .. _N2928: http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2009/n2928.htm
-
-``cxx_func_identifier``
-  Predefined ``__func__`` identifier, as defined in N2340_.
-
-  .. _N2340: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2340.htm
-
-``cxx_generalized_initializers``
-  Initializer lists, as defined in N2672_.
-
-  .. _N2672: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2672.htm
-
-``cxx_inheriting_constructors``
-  Inheriting constructors, as defined in N2540_.
-
-  .. _N2540: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2540.htm
-
-``cxx_inline_namespaces``
-  Inline namespaces, as defined in N2535_.
-
-  .. _N2535: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2535.htm
-
-``cxx_lambdas``
-  Lambda functions, as defined in N2927_.
-
-  .. _N2927: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2927.pdf
-
-``cxx_local_type_template_args``
-  Local and unnamed types as template arguments, as defined in N2657_.
-
-  .. _N2657: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2657.htm
-
-``cxx_long_long_type``
-  ``long long`` type, as defined in N1811_.
-
-  .. _N1811: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1811.pdf
-
-``cxx_noexcept``
-  Exception specifications, as defined in N3050_.
-
-  .. _N3050: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2010/n3050.html
-
-``cxx_nonstatic_member_init``
-  Non-static data member initialization, as defined in N2756.
-
-  .. _N2756: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2756.htm
-
-``cxx_nullptr``
-  Null pointer, as defined in N2431_.
-
-  .. _N2431: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2431.pdf
-
-``cxx_override``
-  Override control ``override`` keyword, as defined in N2928_.
-
-  .. _N2928: http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2009/n2928.htm
-
-``cxx_range_for``
-  Range-based for, as defined in N2930_.
-
-  .. _N2930: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2930.html
-
-``cxx_raw_string_literals``
-  Raw string literals, as defined in N2442_.
-
-  .. _N2442: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2442.htm
-
-``cxx_reference_qualified_functions``
-  Reference qualified functions, as defined in N2439_.
-
-  .. _N2439: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2439.htm
-
-``cxx_right_angle_brackets``
-  Right angle bracket parsing, as defined in N1757_.
-
-  .. _N1757: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1757.html
-
-``cxx_rvalue_references``
-  R-value references, as defined in N2118_.
-
-  .. _N2118: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n2118.html
-
-``cxx_sizeof_member``
-  Size of non-static data members, as defined in N2253_.
-
-  .. _N2253: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2253.html
-
-``cxx_static_assert``
-  Static assert, as defined in N1720_.
-
-  .. _N1720: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2004/n1720.html
-
-``cxx_strong_enums``
-  Strongly typed enums, as defined in N2347_.
-
-  .. _N2347: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2347.pdf
-
-``cxx_thread_local``
-  Thread-local variables, as defined in N2659_.
-
-  .. _N2659: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2659.htm
-
-``cxx_trailing_return_types``
-  Automatic function return type, as defined in N2541_.
-
-  .. _N2541: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2541.htm
-
-``cxx_unicode_literals``
-  Unicode string literals, as defined in N2442_.
-
-  .. _N2442: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2442.htm
-
-``cxx_uniform_initialization``
-  Uniform intialization, as defined in N2640_.
-
-  .. _N2640: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2640.pdf
-
-``cxx_unrestricted_unions``
-  Unrestricted unions, as defined in N2544_.
-
-  .. _N2544: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2544.pdf
-
-``cxx_user_literals``
-  User-defined literals, as defined in N2765_.
-
-  .. _N2765: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2765.pdf
-
-``cxx_variadic_macros``
-  Variadic macros, as defined in N1653_.
-
-  .. _N1653: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2004/n1653.htm
-
-``cxx_variadic_templates``
-  Variadic templates, as defined in N2242_.
-
-  .. _N2242: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2242.pdf
-
-``cxx_template_template_parameters``
-  Template template parameters, as defined in ``ISO/IEC 14882:1998``.