1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
| #if __cplusplus >= 201103L
template<typename _Tp, typename _Alloc>
template<typename... _Args>
#if __cplusplus > 201402L
_GLIBCXX20_CONSTEXPR
typename vector<_Tp, _Alloc>::reference
#else
void
#endif
vector<_Tp, _Alloc>::
emplace_back(_Args&&... __args)
{
if (this->_M_impl._M_finish != this->_M_impl._M_end_of_storage)
{
_GLIBCXX_ASAN_ANNOTATE_GROW(1);
_Alloc_traits::construct(this->_M_impl, this->_M_impl._M_finish,
std::forward<_Args>(__args)...);
++this->_M_impl._M_finish;
_GLIBCXX_ASAN_ANNOTATE_GREW(1);
}
else
_M_realloc_insert(end(), std::forward<_Args>(__args)...);
#if __cplusplus > 201402L
return back();
#endif
}
#endif
#if __cplusplus >= 201103L
template<typename _Tp, typename _Alloc>
template<typename... _Args>
_GLIBCXX20_CONSTEXPR
void
vector<_Tp, _Alloc>::
_M_realloc_insert(iterator __position, _Args&&... __args)
#else
template<typename _Tp, typename _Alloc>
void
vector<_Tp, _Alloc>::
_M_realloc_insert(iterator __position, const _Tp& __x)
#endif
{
// 计算新容量
const size_type __len =
_M_check_len(size_type(1), "vector::_M_realloc_insert");
pointer __old_start = this->_M_impl._M_start;
pointer __old_finish = this->_M_impl._M_finish;
const size_type __elems_before = __position - begin();
pointer __new_start(this->_M_allocate(__len));
pointer __new_finish(__new_start);
__try
{
// The order of the three operations is dictated by the C++11
// case, where the moves could alter a new element belonging
// to the existing vector. This is an issue only for callers
// taking the element by lvalue ref (see last bullet of C++11
// [res.on.arguments]).
_Alloc_traits::construct(this->_M_impl,
__new_start + __elems_before,
#if __cplusplus >= 201103L
std::forward<_Args>(__args)...);
#else
__x);
#endif
__new_finish = pointer();
#if __cplusplus >= 201103L
if _GLIBCXX17_CONSTEXPR (_S_use_relocate())
{
__new_finish = _S_relocate(__old_start, __position.base(),
__new_start, _M_get_Tp_allocator());
++__new_finish;
__new_finish = _S_relocate(__position.base(), __old_finish,
__new_finish, _M_get_Tp_allocator());
}
else
#endif
{
__new_finish
= std::__uninitialized_move_if_noexcept_a
(__old_start, __position.base(),
__new_start, _M_get_Tp_allocator());
++__new_finish;
__new_finish
= std::__uninitialized_move_if_noexcept_a
(__position.base(), __old_finish,
__new_finish, _M_get_Tp_allocator());
}
}
__catch(...)
{
if (!__new_finish)
_Alloc_traits::destroy(this->_M_impl,
__new_start + __elems_before);
else
std::_Destroy(__new_start, __new_finish, _M_get_Tp_allocator());
_M_deallocate(__new_start, __len);
__throw_exception_again;
}
#if __cplusplus >= 201103L
if _GLIBCXX17_CONSTEXPR (!_S_use_relocate())
#endif
std::_Destroy(__old_start, __old_finish, _M_get_Tp_allocator());
_GLIBCXX_ASAN_ANNOTATE_REINIT;
_M_deallocate(__old_start,
this->_M_impl._M_end_of_storage - __old_start);
this->_M_impl._M_start = __new_start;
this->_M_impl._M_finish = __new_finish;
this->_M_impl._M_end_of_storage = __new_start + __len;
}
_GLIBCXX20_CONSTEXPR
size_type
_M_check_len(size_type __n, const char* __s) const
{
if (max_size() - size() < __n)
__throw_length_error(__N(__s));
// 新容量 = 当前大小 + max(当前大小, 1)
const size_type __len = size() + (std::max)(size(), __n);
return (__len < size() || __len > max_size()) ? max_size() : __len;
}
|