| // Reference-counted versatile string base -*- C++ -*- |
| |
| // Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 |
| // Free Software Foundation, Inc. |
| // |
| // This file is part of the GNU ISO C++ Library. This library is free |
| // software; you can redistribute it and/or modify it under the |
| // terms of the GNU General Public License as published by the |
| // Free Software Foundation; either version 3, or (at your option) |
| // any later version. |
| |
| // This library is distributed in the hope that it will be useful, |
| // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| // GNU General Public License for more details. |
| |
| // Under Section 7 of GPL version 3, you are granted additional |
| // permissions described in the GCC Runtime Library Exception, version |
| // 3.1, as published by the Free Software Foundation. |
| |
| // You should have received a copy of the GNU General Public License and |
| // a copy of the GCC Runtime Library Exception along with this program; |
| // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
| // <http://www.gnu.org/licenses/>. |
| |
| /** @file ext/rc_string_base.h |
| * This file is a GNU extension to the Standard C++ Library. |
| * This is an internal header file, included by other library headers. |
| * You should not attempt to use it directly. |
| */ |
| |
| #ifndef _RC_STRING_BASE_H |
| #define _RC_STRING_BASE_H 1 |
| |
| #include <ext/atomicity.h> |
| #include <bits/stl_iterator_base_funcs.h> |
| |
| _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx) |
| |
| /** |
| * Documentation? What's that? |
| * Nathan Myers <ncm@cantrip.org>. |
| * |
| * A string looks like this: |
| * |
| * @code |
| * [_Rep] |
| * _M_length |
| * [__rc_string_base<char_type>] _M_capacity |
| * _M_dataplus _M_refcount |
| * _M_p ----------------> unnamed array of char_type |
| * @endcode |
| * |
| * Where the _M_p points to the first character in the string, and |
| * you cast it to a pointer-to-_Rep and subtract 1 to get a |
| * pointer to the header. |
| * |
| * This approach has the enormous advantage that a string object |
| * requires only one allocation. All the ugliness is confined |
| * within a single pair of inline functions, which each compile to |
| * a single @a add instruction: _Rep::_M_refdata(), and |
| * __rc_string_base::_M_rep(); and the allocation function which gets a |
| * block of raw bytes and with room enough and constructs a _Rep |
| * object at the front. |
| * |
| * The reason you want _M_data pointing to the character array and |
| * not the _Rep is so that the debugger can see the string |
| * contents. (Probably we should add a non-inline member to get |
| * the _Rep for the debugger to use, so users can check the actual |
| * string length.) |
| * |
| * Note that the _Rep object is a POD so that you can have a |
| * static <em>empty string</em> _Rep object already @a constructed before |
| * static constructors have run. The reference-count encoding is |
| * chosen so that a 0 indicates one reference, so you never try to |
| * destroy the empty-string _Rep object. |
| * |
| * All but the last paragraph is considered pretty conventional |
| * for a C++ string implementation. |
| */ |
| template<typename _CharT, typename _Traits, typename _Alloc> |
| class __rc_string_base |
| : protected __vstring_utility<_CharT, _Traits, _Alloc> |
| { |
| public: |
| typedef _Traits traits_type; |
| typedef typename _Traits::char_type value_type; |
| typedef _Alloc allocator_type; |
| |
| typedef __vstring_utility<_CharT, _Traits, _Alloc> _Util_Base; |
| typedef typename _Util_Base::_CharT_alloc_type _CharT_alloc_type; |
| typedef typename _CharT_alloc_type::size_type size_type; |
| |
| private: |
| // _Rep: string representation |
| // Invariants: |
| // 1. String really contains _M_length + 1 characters: due to 21.3.4 |
| // must be kept null-terminated. |
| // 2. _M_capacity >= _M_length |
| // Allocated memory is always (_M_capacity + 1) * sizeof(_CharT). |
| // 3. _M_refcount has three states: |
| // -1: leaked, one reference, no ref-copies allowed, non-const. |
| // 0: one reference, non-const. |
| // n>0: n + 1 references, operations require a lock, const. |
| // 4. All fields == 0 is an empty string, given the extra storage |
| // beyond-the-end for a null terminator; thus, the shared |
| // empty string representation needs no constructor. |
| struct _Rep |
| { |
| union |
| { |
| struct |
| { |
| size_type _M_length; |
| size_type _M_capacity; |
| _Atomic_word _M_refcount; |
| } _M_info; |
| |
| // Only for alignment purposes. |
| _CharT _M_align; |
| }; |
| |
| typedef typename _Alloc::template rebind<_Rep>::other _Rep_alloc_type; |
| |
| _CharT* |
| _M_refdata() throw() |
| { return reinterpret_cast<_CharT*>(this + 1); } |
| |
| _CharT* |
| _M_refcopy() throw() |
| { |
| __atomic_add_dispatch(&_M_info._M_refcount, 1); |
| return _M_refdata(); |
| } // XXX MT |
| |
| void |
| _M_set_length(size_type __n) |
| { |
| _M_info._M_refcount = 0; // One reference. |
| _M_info._M_length = __n; |
| // grrr. (per 21.3.4) |
| // You cannot leave those LWG people alone for a second. |
| traits_type::assign(_M_refdata()[__n], _CharT()); |
| } |
| |
| // Create & Destroy |
| static _Rep* |
| _S_create(size_type, size_type, const _Alloc&); |
| |
| void |
| _M_destroy(const _Alloc&) throw(); |
| |
| _CharT* |
| _M_clone(const _Alloc&, size_type __res = 0); |
| }; |
| |
| struct _Rep_empty |
| : public _Rep |
| { |
| _CharT _M_terminal; |
| }; |
| |
| static _Rep_empty _S_empty_rep; |
| |
| // The maximum number of individual char_type elements of an |
| // individual string is determined by _S_max_size. This is the |
| // value that will be returned by max_size(). (Whereas npos |
| // is the maximum number of bytes the allocator can allocate.) |
| // If one was to divvy up the theoretical largest size string, |
| // with a terminating character and m _CharT elements, it'd |
| // look like this: |
| // npos = sizeof(_Rep) + (m * sizeof(_CharT)) + sizeof(_CharT) |
| // + sizeof(_Rep) - 1 |
| // (NB: last two terms for rounding reasons, see _M_create below) |
| // Solving for m: |
| // m = ((npos - 2 * sizeof(_Rep) + 1) / sizeof(_CharT)) - 1 |
| // In addition, this implementation halves this amount. |
| enum { _S_max_size = (((static_cast<size_type>(-1) - 2 * sizeof(_Rep) |
| + 1) / sizeof(_CharT)) - 1) / 2 }; |
| |
| // Data Member (private): |
| mutable typename _Util_Base::template _Alloc_hider<_Alloc> _M_dataplus; |
| |
| void |
| _M_data(_CharT* __p) |
| { _M_dataplus._M_p = __p; } |
| |
| _Rep* |
| _M_rep() const |
| { return &((reinterpret_cast<_Rep*>(_M_data()))[-1]); } |
| |
| _CharT* |
| _M_grab(const _Alloc& __alloc) const |
| { |
| return (!_M_is_leaked() && _M_get_allocator() == __alloc) |
| ? _M_rep()->_M_refcopy() : _M_rep()->_M_clone(__alloc); |
| } |
| |
| void |
| _M_dispose() |
| { |
| if (__exchange_and_add_dispatch(&_M_rep()->_M_info._M_refcount, |
| -1) <= 0) |
| _M_rep()->_M_destroy(_M_get_allocator()); |
| } // XXX MT |
| |
| bool |
| _M_is_leaked() const |
| { return _M_rep()->_M_info._M_refcount < 0; } |
| |
| void |
| _M_set_sharable() |
| { _M_rep()->_M_info._M_refcount = 0; } |
| |
| void |
| _M_leak_hard(); |
| |
| // _S_construct_aux is used to implement the 21.3.1 para 15 which |
| // requires special behaviour if _InIterator is an integral type |
| template<typename _InIterator> |
| static _CharT* |
| _S_construct_aux(_InIterator __beg, _InIterator __end, |
| const _Alloc& __a, std::__false_type) |
| { |
| typedef typename iterator_traits<_InIterator>::iterator_category _Tag; |
| return _S_construct(__beg, __end, __a, _Tag()); |
| } |
| |
| // _GLIBCXX_RESOLVE_LIB_DEFECTS |
| // 438. Ambiguity in the "do the right thing" clause |
| template<typename _Integer> |
| static _CharT* |
| _S_construct_aux(_Integer __beg, _Integer __end, |
| const _Alloc& __a, std::__true_type) |
| { return _S_construct_aux_2(static_cast<size_type>(__beg), |
| __end, __a); } |
| |
| static _CharT* |
| _S_construct_aux_2(size_type __req, _CharT __c, const _Alloc& __a) |
| { return _S_construct(__req, __c, __a); } |
| |
| template<typename _InIterator> |
| static _CharT* |
| _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a) |
| { |
| typedef typename std::__is_integer<_InIterator>::__type _Integral; |
| return _S_construct_aux(__beg, __end, __a, _Integral()); |
| } |
| |
| // For Input Iterators, used in istreambuf_iterators, etc. |
| template<typename _InIterator> |
| static _CharT* |
| _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a, |
| std::input_iterator_tag); |
| |
| // For forward_iterators up to random_access_iterators, used for |
| // string::iterator, _CharT*, etc. |
| template<typename _FwdIterator> |
| static _CharT* |
| _S_construct(_FwdIterator __beg, _FwdIterator __end, const _Alloc& __a, |
| std::forward_iterator_tag); |
| |
| static _CharT* |
| _S_construct(size_type __req, _CharT __c, const _Alloc& __a); |
| |
| public: |
| size_type |
| _M_max_size() const |
| { return size_type(_S_max_size); } |
| |
| _CharT* |
| _M_data() const |
| { return _M_dataplus._M_p; } |
| |
| size_type |
| _M_length() const |
| { return _M_rep()->_M_info._M_length; } |
| |
| size_type |
| _M_capacity() const |
| { return _M_rep()->_M_info._M_capacity; } |
| |
| bool |
| _M_is_shared() const |
| { return _M_rep()->_M_info._M_refcount > 0; } |
| |
| void |
| _M_set_leaked() |
| { _M_rep()->_M_info._M_refcount = -1; } |
| |
| void |
| _M_leak() // for use in begin() & non-const op[] |
| { |
| if (!_M_is_leaked()) |
| _M_leak_hard(); |
| } |
| |
| void |
| _M_set_length(size_type __n) |
| { _M_rep()->_M_set_length(__n); } |
| |
| __rc_string_base() |
| : _M_dataplus(_S_empty_rep._M_refcopy()) { } |
| |
| __rc_string_base(const _Alloc& __a); |
| |
| __rc_string_base(const __rc_string_base& __rcs); |
| |
| #ifdef __GXX_EXPERIMENTAL_CXX0X__ |
| __rc_string_base(__rc_string_base&& __rcs) |
| : _M_dataplus(__rcs._M_dataplus) |
| { __rcs._M_data(_S_empty_rep._M_refcopy()); } |
| #endif |
| |
| __rc_string_base(size_type __n, _CharT __c, const _Alloc& __a); |
| |
| template<typename _InputIterator> |
| __rc_string_base(_InputIterator __beg, _InputIterator __end, |
| const _Alloc& __a); |
| |
| ~__rc_string_base() |
| { _M_dispose(); } |
| |
| allocator_type& |
| _M_get_allocator() |
| { return _M_dataplus; } |
| |
| const allocator_type& |
| _M_get_allocator() const |
| { return _M_dataplus; } |
| |
| void |
| _M_swap(__rc_string_base& __rcs); |
| |
| void |
| _M_assign(const __rc_string_base& __rcs); |
| |
| void |
| _M_reserve(size_type __res); |
| |
| void |
| _M_mutate(size_type __pos, size_type __len1, const _CharT* __s, |
| size_type __len2); |
| |
| void |
| _M_erase(size_type __pos, size_type __n); |
| |
| void |
| _M_clear() |
| { _M_erase(size_type(0), _M_length()); } |
| |
| bool |
| _M_compare(const __rc_string_base&) const |
| { return false; } |
| }; |
| |
| template<typename _CharT, typename _Traits, typename _Alloc> |
| typename __rc_string_base<_CharT, _Traits, _Alloc>::_Rep_empty |
| __rc_string_base<_CharT, _Traits, _Alloc>::_S_empty_rep; |
| |
| template<typename _CharT, typename _Traits, typename _Alloc> |
| typename __rc_string_base<_CharT, _Traits, _Alloc>::_Rep* |
| __rc_string_base<_CharT, _Traits, _Alloc>::_Rep:: |
| _S_create(size_type __capacity, size_type __old_capacity, |
| const _Alloc& __alloc) |
| { |
| // _GLIBCXX_RESOLVE_LIB_DEFECTS |
| // 83. String::npos vs. string::max_size() |
| if (__capacity > size_type(_S_max_size)) |
| std::__throw_length_error(__N("__rc_string_base::_Rep::_S_create")); |
| |
| // The standard places no restriction on allocating more memory |
| // than is strictly needed within this layer at the moment or as |
| // requested by an explicit application call to reserve(). |
| |
| // Many malloc implementations perform quite poorly when an |
| // application attempts to allocate memory in a stepwise fashion |
| // growing each allocation size by only 1 char. Additionally, |
| // it makes little sense to allocate less linear memory than the |
| // natural blocking size of the malloc implementation. |
| // Unfortunately, we would need a somewhat low-level calculation |
| // with tuned parameters to get this perfect for any particular |
| // malloc implementation. Fortunately, generalizations about |
| // common features seen among implementations seems to suffice. |
| |
| // __pagesize need not match the actual VM page size for good |
| // results in practice, thus we pick a common value on the low |
| // side. __malloc_header_size is an estimate of the amount of |
| // overhead per memory allocation (in practice seen N * sizeof |
| // (void*) where N is 0, 2 or 4). According to folklore, |
| // picking this value on the high side is better than |
| // low-balling it (especially when this algorithm is used with |
| // malloc implementations that allocate memory blocks rounded up |
| // to a size which is a power of 2). |
| const size_type __pagesize = 4096; |
| const size_type __malloc_header_size = 4 * sizeof(void*); |
| |
| // The below implements an exponential growth policy, necessary to |
| // meet amortized linear time requirements of the library: see |
| // http://gcc.gnu.org/ml/libstdc++/2001-07/msg00085.html. |
| if (__capacity > __old_capacity && __capacity < 2 * __old_capacity) |
| { |
| __capacity = 2 * __old_capacity; |
| // Never allocate a string bigger than _S_max_size. |
| if (__capacity > size_type(_S_max_size)) |
| __capacity = size_type(_S_max_size); |
| } |
| |
| // NB: Need an array of char_type[__capacity], plus a terminating |
| // null char_type() element, plus enough for the _Rep data structure, |
| // plus sizeof(_Rep) - 1 to upper round to a size multiple of |
| // sizeof(_Rep). |
| // Whew. Seemingly so needy, yet so elemental. |
| size_type __size = ((__capacity + 1) * sizeof(_CharT) |
| + 2 * sizeof(_Rep) - 1); |
| |
| const size_type __adj_size = __size + __malloc_header_size; |
| if (__adj_size > __pagesize && __capacity > __old_capacity) |
| { |
| const size_type __extra = __pagesize - __adj_size % __pagesize; |
| __capacity += __extra / sizeof(_CharT); |
| if (__capacity > size_type(_S_max_size)) |
| __capacity = size_type(_S_max_size); |
| __size = (__capacity + 1) * sizeof(_CharT) + 2 * sizeof(_Rep) - 1; |
| } |
| |
| // NB: Might throw, but no worries about a leak, mate: _Rep() |
| // does not throw. |
| _Rep* __place = _Rep_alloc_type(__alloc).allocate(__size / sizeof(_Rep)); |
| _Rep* __p = new (__place) _Rep; |
| __p->_M_info._M_capacity = __capacity; |
| return __p; |
| } |
| |
| template<typename _CharT, typename _Traits, typename _Alloc> |
| void |
| __rc_string_base<_CharT, _Traits, _Alloc>::_Rep:: |
| _M_destroy(const _Alloc& __a) throw () |
| { |
| const size_type __size = ((_M_info._M_capacity + 1) * sizeof(_CharT) |
| + 2 * sizeof(_Rep) - 1); |
| _Rep_alloc_type(__a).deallocate(this, __size / sizeof(_Rep)); |
| } |
| |
| template<typename _CharT, typename _Traits, typename _Alloc> |
| _CharT* |
| __rc_string_base<_CharT, _Traits, _Alloc>::_Rep:: |
| _M_clone(const _Alloc& __alloc, size_type __res) |
| { |
| // Requested capacity of the clone. |
| const size_type __requested_cap = _M_info._M_length + __res; |
| _Rep* __r = _Rep::_S_create(__requested_cap, _M_info._M_capacity, |
| __alloc); |
| |
| if (_M_info._M_length) |
| _S_copy(__r->_M_refdata(), _M_refdata(), _M_info._M_length); |
| |
| __r->_M_set_length(_M_info._M_length); |
| return __r->_M_refdata(); |
| } |
| |
| template<typename _CharT, typename _Traits, typename _Alloc> |
| __rc_string_base<_CharT, _Traits, _Alloc>:: |
| __rc_string_base(const _Alloc& __a) |
| : _M_dataplus(__a, _S_construct(size_type(), _CharT(), __a)) { } |
| |
| template<typename _CharT, typename _Traits, typename _Alloc> |
| __rc_string_base<_CharT, _Traits, _Alloc>:: |
| __rc_string_base(const __rc_string_base& __rcs) |
| : _M_dataplus(__rcs._M_get_allocator(), |
| __rcs._M_grab(__rcs._M_get_allocator())) { } |
| |
| template<typename _CharT, typename _Traits, typename _Alloc> |
| __rc_string_base<_CharT, _Traits, _Alloc>:: |
| __rc_string_base(size_type __n, _CharT __c, const _Alloc& __a) |
| : _M_dataplus(__a, _S_construct(__n, __c, __a)) { } |
| |
| template<typename _CharT, typename _Traits, typename _Alloc> |
| template<typename _InputIterator> |
| __rc_string_base<_CharT, _Traits, _Alloc>:: |
| __rc_string_base(_InputIterator __beg, _InputIterator __end, |
| const _Alloc& __a) |
| : _M_dataplus(__a, _S_construct(__beg, __end, __a)) { } |
| |
| template<typename _CharT, typename _Traits, typename _Alloc> |
| void |
| __rc_string_base<_CharT, _Traits, _Alloc>:: |
| _M_leak_hard() |
| { |
| if (_M_is_shared()) |
| _M_erase(0, 0); |
| _M_set_leaked(); |
| } |
| |
| // NB: This is the special case for Input Iterators, used in |
| // istreambuf_iterators, etc. |
| // Input Iterators have a cost structure very different from |
| // pointers, calling for a different coding style. |
| template<typename _CharT, typename _Traits, typename _Alloc> |
| template<typename _InIterator> |
| _CharT* |
| __rc_string_base<_CharT, _Traits, _Alloc>:: |
| _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a, |
| std::input_iterator_tag) |
| { |
| if (__beg == __end && __a == _Alloc()) |
| return _S_empty_rep._M_refcopy(); |
| |
| // Avoid reallocation for common case. |
| _CharT __buf[128]; |
| size_type __len = 0; |
| while (__beg != __end && __len < sizeof(__buf) / sizeof(_CharT)) |
| { |
| __buf[__len++] = *__beg; |
| ++__beg; |
| } |
| _Rep* __r = _Rep::_S_create(__len, size_type(0), __a); |
| _S_copy(__r->_M_refdata(), __buf, __len); |
| __try |
| { |
| while (__beg != __end) |
| { |
| if (__len == __r->_M_info._M_capacity) |
| { |
| // Allocate more space. |
| _Rep* __another = _Rep::_S_create(__len + 1, __len, __a); |
| _S_copy(__another->_M_refdata(), __r->_M_refdata(), __len); |
| __r->_M_destroy(__a); |
| __r = __another; |
| } |
| __r->_M_refdata()[__len++] = *__beg; |
| ++__beg; |
| } |
| } |
| __catch(...) |
| { |
| __r->_M_destroy(__a); |
| __throw_exception_again; |
| } |
| __r->_M_set_length(__len); |
| return __r->_M_refdata(); |
| } |
| |
| template<typename _CharT, typename _Traits, typename _Alloc> |
| template<typename _InIterator> |
| _CharT* |
| __rc_string_base<_CharT, _Traits, _Alloc>:: |
| _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a, |
| std::forward_iterator_tag) |
| { |
| if (__beg == __end && __a == _Alloc()) |
| return _S_empty_rep._M_refcopy(); |
| |
| // NB: Not required, but considered best practice. |
| if (__is_null_pointer(__beg) && __beg != __end) |
| std::__throw_logic_error(__N("__rc_string_base::" |
| "_S_construct NULL not valid")); |
| |
| const size_type __dnew = static_cast<size_type>(std::distance(__beg, |
| __end)); |
| // Check for out_of_range and length_error exceptions. |
| _Rep* __r = _Rep::_S_create(__dnew, size_type(0), __a); |
| __try |
| { _S_copy_chars(__r->_M_refdata(), __beg, __end); } |
| __catch(...) |
| { |
| __r->_M_destroy(__a); |
| __throw_exception_again; |
| } |
| __r->_M_set_length(__dnew); |
| return __r->_M_refdata(); |
| } |
| |
| template<typename _CharT, typename _Traits, typename _Alloc> |
| _CharT* |
| __rc_string_base<_CharT, _Traits, _Alloc>:: |
| _S_construct(size_type __n, _CharT __c, const _Alloc& __a) |
| { |
| if (__n == 0 && __a == _Alloc()) |
| return _S_empty_rep._M_refcopy(); |
| |
| // Check for out_of_range and length_error exceptions. |
| _Rep* __r = _Rep::_S_create(__n, size_type(0), __a); |
| if (__n) |
| _S_assign(__r->_M_refdata(), __n, __c); |
| |
| __r->_M_set_length(__n); |
| return __r->_M_refdata(); |
| } |
| |
| template<typename _CharT, typename _Traits, typename _Alloc> |
| void |
| __rc_string_base<_CharT, _Traits, _Alloc>:: |
| _M_swap(__rc_string_base& __rcs) |
| { |
| if (_M_is_leaked()) |
| _M_set_sharable(); |
| if (__rcs._M_is_leaked()) |
| __rcs._M_set_sharable(); |
| |
| _CharT* __tmp = _M_data(); |
| _M_data(__rcs._M_data()); |
| __rcs._M_data(__tmp); |
| |
| // _GLIBCXX_RESOLVE_LIB_DEFECTS |
| // 431. Swapping containers with unequal allocators. |
| std::__alloc_swap<allocator_type>::_S_do_it(_M_get_allocator(), |
| __rcs._M_get_allocator()); |
| } |
| |
| template<typename _CharT, typename _Traits, typename _Alloc> |
| void |
| __rc_string_base<_CharT, _Traits, _Alloc>:: |
| _M_assign(const __rc_string_base& __rcs) |
| { |
| if (_M_rep() != __rcs._M_rep()) |
| { |
| _CharT* __tmp = __rcs._M_grab(_M_get_allocator()); |
| _M_dispose(); |
| _M_data(__tmp); |
| } |
| } |
| |
| template<typename _CharT, typename _Traits, typename _Alloc> |
| void |
| __rc_string_base<_CharT, _Traits, _Alloc>:: |
| _M_reserve(size_type __res) |
| { |
| // Make sure we don't shrink below the current size. |
| if (__res < _M_length()) |
| __res = _M_length(); |
| |
| if (__res != _M_capacity() || _M_is_shared()) |
| { |
| _CharT* __tmp = _M_rep()->_M_clone(_M_get_allocator(), |
| __res - _M_length()); |
| _M_dispose(); |
| _M_data(__tmp); |
| } |
| } |
| |
| template<typename _CharT, typename _Traits, typename _Alloc> |
| void |
| __rc_string_base<_CharT, _Traits, _Alloc>:: |
| _M_mutate(size_type __pos, size_type __len1, const _CharT* __s, |
| size_type __len2) |
| { |
| const size_type __how_much = _M_length() - __pos - __len1; |
| |
| _Rep* __r = _Rep::_S_create(_M_length() + __len2 - __len1, |
| _M_capacity(), _M_get_allocator()); |
| |
| if (__pos) |
| _S_copy(__r->_M_refdata(), _M_data(), __pos); |
| if (__s && __len2) |
| _S_copy(__r->_M_refdata() + __pos, __s, __len2); |
| if (__how_much) |
| _S_copy(__r->_M_refdata() + __pos + __len2, |
| _M_data() + __pos + __len1, __how_much); |
| |
| _M_dispose(); |
| _M_data(__r->_M_refdata()); |
| } |
| |
| template<typename _CharT, typename _Traits, typename _Alloc> |
| void |
| __rc_string_base<_CharT, _Traits, _Alloc>:: |
| _M_erase(size_type __pos, size_type __n) |
| { |
| const size_type __new_size = _M_length() - __n; |
| const size_type __how_much = _M_length() - __pos - __n; |
| |
| if (_M_is_shared()) |
| { |
| // Must reallocate. |
| _Rep* __r = _Rep::_S_create(__new_size, _M_capacity(), |
| _M_get_allocator()); |
| |
| if (__pos) |
| _S_copy(__r->_M_refdata(), _M_data(), __pos); |
| if (__how_much) |
| _S_copy(__r->_M_refdata() + __pos, |
| _M_data() + __pos + __n, __how_much); |
| |
| _M_dispose(); |
| _M_data(__r->_M_refdata()); |
| } |
| else if (__how_much && __n) |
| { |
| // Work in-place. |
| _S_move(_M_data() + __pos, |
| _M_data() + __pos + __n, __how_much); |
| } |
| |
| _M_rep()->_M_set_length(__new_size); |
| } |
| |
| template<> |
| inline bool |
| __rc_string_base<char, std::char_traits<char>, |
| std::allocator<char> >:: |
| _M_compare(const __rc_string_base& __rcs) const |
| { |
| if (_M_rep() == __rcs._M_rep()) |
| return true; |
| return false; |
| } |
| |
| #ifdef _GLIBCXX_USE_WCHAR_T |
| template<> |
| inline bool |
| __rc_string_base<wchar_t, std::char_traits<wchar_t>, |
| std::allocator<wchar_t> >:: |
| _M_compare(const __rc_string_base& __rcs) const |
| { |
| if (_M_rep() == __rcs._M_rep()) |
| return true; |
| return false; |
| } |
| #endif |
| |
| _GLIBCXX_END_NAMESPACE |
| |
| #endif /* _RC_STRING_BASE_H */ |
