The macro definitions in <version> should depend on the same
preprocessor conditions as the original macros in other headers.
Otherwise <version> can define macros that imply the availability of
features that are not actually defined.
This fix is incomplete, as __cpp_lib_filesystem should depend on whether
libstdc++fs.a is supported, and several macros should only be defined
when _GLIBCXX_HOSTED is defined. Also, the feature test macros should
define their value as type long, but most are type int.
* include/bits/c++config (_GLIBCXX_HAVE_BUILTIN_HAS_UNIQ_OBJ_REP)
(_GLIBCXX_HAVE_BUILTIN_IS_AGGREGATE): Move definitions here.
(_GLIBCXX_HAVE_BUILTIN_LAUNDER): Likewise. Use !__is_identifier
instead of __has_builtin.
* include/std/type_traits (_GLIBCXX_HAVE_BUILTIN_HAS_UNIQ_OBJ_REP)
(_GLIBCXX_HAVE_BUILTIN_IS_AGGREGATE): Remove definitions from here.
* include/std/version [!_GLIBCXX_HAS_GTHREADS]
(__cpp_lib_shared_timed_mutex, __cpp_lib_scoped_lock)
(__cpp_lib_shared_mutex): Don't define when Gthreads not in use.
[!_GLIBCXX_HAVE_BUILTIN_HAS_UNIQ_OBJ_REP]
(__cpp_lib_has_unique_object_representations): Don't define when
builtin not available.
[!_GLIBCXX_HAVE_BUILTIN_IS_AGGREGATE] (__cpp_lib_is_aggregate):
Likewise.
[!_GLIBCXX_HAVE_BUILTIN_LAUNDER] (__cpp_lib_launder): Likewise.
* libsupc++/new (_GLIBCXX_HAVE_BUILTIN_LAUNDER): Remove definition
from here.
From-SVN: r263184
