59 #pragma GCC system_header 
   63 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
 
   65 _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
   78   template <
class _Key, 
class _Value, 
class _KeyOfValue, 
class _Compare,
 
   79         class _Alloc = allocator<_Value> >
 
   81     : 
public _Rb_tree<_Key, _Value, _KeyOfValue, _Compare, _Alloc>
 
   83       typedef _Rb_tree<_Key, _Value, _KeyOfValue, _Compare, _Alloc> _Base;
 
   84       typedef typename _Base::allocator_type allocator_type;
 
   86       rb_tree(
const _Compare& __comp = _Compare(),
 
   87           const allocator_type& __a = allocator_type())
 
   88       : _Base(__comp, __a) { }
 
   93 _GLIBCXX_END_NAMESPACE_VERSION
 
The standard allocator, as per [20.4].Further details: http://gcc.gnu.org/onlinedocs/libstdc++/manual...