46#pragma GCC system_header
50namespace std _GLIBCXX_VISIBILITY(default)
52_GLIBCXX_BEGIN_NAMESPACE_VERSION
66#if __cplusplus <= 201703L
68 class allocator<void>;
71#if __cplusplus >= 201103L
73 template<
typename,
typename>
74 struct uses_allocator;
79_GLIBCXX_END_NAMESPACE_VERSION
ISO C++ entities toplevel namespace is std.