diff options
Diffstat (limited to 'libstdc++-v3/include/ext/vstring_util.h')
| -rw-r--r-- | libstdc++-v3/include/ext/vstring_util.h | 59 |
1 files changed, 48 insertions, 11 deletions
diff --git a/libstdc++-v3/include/ext/vstring_util.h b/libstdc++-v3/include/ext/vstring_util.h index 38c7c10976a..2a53fbdd4bd 100644 --- a/libstdc++-v3/include/ext/vstring_util.h +++ b/libstdc++-v3/include/ext/vstring_util.h @@ -1,4 +1,4 @@ -// Versatile string utilities -*- C++ -*- +// Versatile string utility -*- C++ -*- // Copyright (C) 2005 Free Software Foundation, Inc. // @@ -47,16 +47,6 @@ namespace __gnu_cxx { - template<typename _Type> - inline bool - __is_null_p(_Type* __ptr) - { return __ptr == 0; } - - template<typename _Type> - inline bool - __is_null_p(_Type) - { return false; } - template<typename _CharT, typename _Traits, typename _Alloc> struct __vstring_utility { @@ -92,6 +82,53 @@ namespace __gnu_cxx __rc_string_base> > __const_rc_iterator; + // NB: When the allocator is empty, deriving from it saves space + // (http://www.cantrip.org/emptyopt.html). We do that anyway for + // consistency. + template<typename _Alloc1, bool = std::__is_empty<_Alloc1>::__value> + struct _Alloc_hider + : public _Alloc1 + { + _Alloc_hider(const _Alloc1& __a, _CharT* __ptr) + : _Alloc1(__a), _M_p(__ptr) { } + + void + _M_alloc_swap(_Alloc_hider& __ah) + { + // Implement Option 3 of DR 431 (see N1599). + // Precondition: swappable allocators. + _Alloc1& __this = static_cast<_Alloc1&>(*this); + _Alloc1& __that = static_cast<_Alloc1&>(__ah); + if (__this != __that) + swap(__this, __that); + } + + _CharT* _M_p; // The actual data. + }; + + template<typename _Alloc1> + struct _Alloc_hider<_Alloc1, true> + : public _Alloc1 + { + _Alloc_hider(const _Alloc1& __a, _CharT* __ptr) + : _Alloc1(__a), _M_p(__ptr) { } + + void _M_alloc_swap(_Alloc_hider&) { } + + _CharT* _M_p; // The actual data. + }; + + // For use in _M_construct (_S_construct) forward_iterator_tag. + template<typename _Type> + static bool + _S_is_null_pointer(_Type* __ptr) + { return __ptr == 0; } + + template<typename _Type> + static bool + _S_is_null_pointer(_Type) + { return false; } + // When __n = 1 way faster than the general multichar // traits_type::copy/move/assign. static void |