头文件
c++/5/bits/stl_construct.h
c++/5/bits/stl_uninitialized.h
源代码及解析
stl_construct.h解析
//已经给对象分配空间的情况下，构造对象。
#if __cplusplus >= 201103L
template
inline void
_Construct(_T1* __p, _Args&&... __args)
{ ::new(static_cast(__p)) _T1(std::forward<_Args>(__args)...); }
#else
template
inline void
_Construct(_T1* __p, const _T2& __value)
{
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 402. wrong new expression in [some_]allocator::construct
::new(static_cast(__p)) _T1(__value);
}
#endif
/**
* Destroy the object pointed to by a pointer type.
*/
// 调用对象的析构函数
template
inline void
_Destroy(_Tp* __pointer)
{ __pointer->~_Tp(); }
//模板类，析构一个连续空间的数组对象
template
struct _Destroy_aux
{
template
static void
__destroy(_ForwardIterator __first, _ForwardIterator __last)
{
for (; __first != __last; ++__first)
std::_Destroy(std::__addressof(*__first));
}
};
// 模板类 特化，啥都没干
template<>
struct _Destroy_aux
{
template
static void
__destroy(_ForwardIterator, _ForwardIterator) { }
};
/**
* Destroy a range of objects. If the value_type of the object has
* a trivial destructor, the compiler should optimize all of this
* away, otherwise the objects' destructors must be invoked.
*/
//析构一个连续空间的数组对象
template
inline void
_Destroy(_ForwardIterator __first, _ForwardIterator __last)
{
typedef typename iterator_traits<_ForwardIterator>::value_type
_Value_type;
std::_Destroy_aux<__has_trivial_destructor(_Value_type)>::
__destroy(__first, __last);
}
/**
* Destroy a range of objects using the supplied allocator. For
* nondefault allocators we do not optimize away invocation of
* destroy() even if _Tp has a trivial destructor.
*/
//一个连续空间的数组对象
template
void
_Destroy(_ForwardIterator __first, _ForwardIterator __last,
_Allocator& __alloc)
{
typedef __gnu_cxx::__alloc_traits<_Allocator> __traits;
for (; __first != __last; ++__first)
__traits::destroy(__alloc, std::__addressof(*__first));
}
//一个连续空间的数组对象
template
inline void
_Destroy(_ForwardIterator __first, _ForwardIterator __last,
allocator<_Tp>&)
{
_Destroy(__first, __last);
}
stl_uninitialized.h
//模板类 将 [_InputIterator, _ForwardIterator)区间的元素
//拷贝到 起始空间为 __result的空间去。
template
struct __uninitialized_copy
{
template
static _ForwardIterator
__uninit_copy(_InputIterator __first, _InputIterator __last,
_ForwardIterator __result)
{
_ForwardIterator __cur = __result;
__try
{
for (; __first != __last; ++__first, ++__cur)
std::_Construct(std::__addressof(*__cur), *__first);
return __cur;
}
__catch(...)
{
std::_Destroy(__result, __cur);
__throw_exception_again;
}
}
};
//模板类 特化，与模板类功能一样。
template<>
struct __uninitialized_copy
{
template
static _ForwardIterator
__uninit_copy(_InputIterator __first, _InputIterator __last,
_ForwardIterator __result)
{ return std::copy(__first, __last, __result); }
};
/**
* @brief Copies the range [first,last) into result.
* @param __first An input iterator.
* @param __last An input iterator.
* @param __result An output iterator.
* @return __result + (__first - __last)
*
* Like copy(), but does not require an initialized output range.
*/
//模板函数， 与 上述模板类 功能一样。
template
inline _ForwardIterator
uninitialized_copy(_InputIterator __first, _InputIterator __last,
_ForwardIterator __result)
{
typedef typename iterator_traits<_InputIterator>::value_type
_ValueType1;
typedef typename iterator_traits<_ForwardIterator>::value_type
_ValueType2;
#if __cplusplus < 201103L
const bool __assignable = true;
#else
// trivial types can have deleted assignment
typedef typename iterator_traits<_InputIterator>::reference _RefType1;
typedef typename iterator_traits<_ForwardIterator>::reference _RefType2;
const bool __assignable = is_assignable<_RefType2, _RefType1>::value;
#endif
return std::__uninitialized_copy<__is_trivial(_ValueType1)
&& __is_trivial(_ValueType2)
&& __assignable>::
__uninit_copy(__first, __last, __result);
}
//模板类 将 [_InputIterator, _ForwardIterator)区间的元素
// 填充为 __x
template
struct __uninitialized_fill
{
template
static void
__uninit_fill(_ForwardIterator __first, _ForwardIterator __last,
const _Tp& __x)
{
_ForwardIterator __cur = __first;
__try
{
for (; __cur != __last; ++__cur)
std::_Construct(std::__addressof(*__cur), __x);
}
__catch(...)
{
std::_Destroy(__first, __cur);
__throw_exception_again;
}
}
};
//模板类 特化
template<>
struct __uninitialized_fill
{
template
static void
__uninit_fill(_ForwardIterator __first, _ForwardIterator __last,
const _Tp& __x)
{ std::fill(__first, __last, __x); }
};
/**
* @brief Copies the value x into the range [first,last).
* @param __first An input iterator.
* @param __last An input iterator.
* @param __x The source value.
* @return Nothing.
*
* Like fill(), but does not require an initialized output range.
*/
//模板函数 将 [_InputIterator, _ForwardIterator)区间的元素
// 填充为 __x
template
inline void
uninitialized_fill(_ForwardIterator __first, _ForwardIterator __last,
const _Tp& __x)
{
typedef typename iterator_traits<_ForwardIterator>::value_type
_ValueType;
#if __cplusplus < 201103L
const bool __assignable = true;
#else
// trivial types can have deleted assignment
const bool __assignable = is_copy_assignable<_ValueType>::value;
#endif
std::__uninitialized_fill<__is_trivial(_ValueType) && __assignable>::
__uninit_fill(__first, __last, __x);
}
//模板类 将 [_InputIterator, _InputIterator+n)区间的元素
// 填充为 __x
template
struct __uninitialized_fill_n
{
template
static _ForwardIterator
__uninit_fill_n(_ForwardIterator __first, _Size __n,
const _Tp& __x)
{
_ForwardIterator __cur = __first;
__try
{
for (; __n > 0; --__n, ++__cur)
std::_Construct(std::__addressof(*__cur), __x);
return __cur;
}
__catch(...)
{
std::_Destroy(__first, __cur);
__throw_exception_again;
}
}
};
//模板类 特化
template<>
struct __uninitialized_fill_n
{
template
static _ForwardIterator
__uninit_fill_n(_ForwardIterator __first, _Size __n,
const _Tp& __x)
{ return std::fill_n(__first, __n, __x); }
};
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// DR 1339. uninitialized_fill_n should return the end of its range
/**
* @brief Copies the value x into the range [first,first+n).
* @param __first An input iterator.
* @param __n The number of copies to make.
* @param __x The source value.
* @return Nothing.
*
* Like fill_n(), but does not require an initialized output range.
*/
//模板函数 将 [_InputIterator, _InputIterator+n)区间的元素
// 填充为 __x
template
inline _ForwardIterator
uninitialized_fill_n(_ForwardIterator __first, _Size __n, const _Tp& __x)
{
typedef typename iterator_traits<_ForwardIterator>::value_type
_ValueType;
#if __cplusplus < 201103L
const bool __assignable = true;
#else
// trivial types can have deleted assignment
const bool __assignable = is_copy_assignable<_ValueType>::value;
#endif
return __uninitialized_fill_n<__is_trivial(_ValueType) && __assignable>::
__uninit_fill_n(__first, __n, __x);
}
// Extensions: versions of uninitialized_copy, uninitialized_fill,
// and uninitialized_fill_n that take an allocator parameter.
// We dispatch back to the standard versions when we're given the
// default allocator. For nondefault allocators we do not use
// any of the POD optimizations.
template
_ForwardIterator
__uninitialized_copy_a(_InputIterator __first, _InputIterator __last,
_ForwardIterator __result, _Allocator& __alloc)
{
_ForwardIterator __cur = __result;
__try
{
typedef __gnu_cxx::__alloc_traits<_Allocator> __traits;
for (; __first != __last; ++__first, ++__cur)
__traits::construct(__alloc, std::__addressof(*__cur), *__first);
return __cur;
}
__catch(...)
{
std::_Destroy(__result, __cur, __alloc);
__throw_exception_again;
}
}
template
inline _ForwardIterator
__uninitialized_copy_a(_InputIterator __first, _InputIterator __last,
_ForwardIterator __result, allocator<_Tp>&)
{ return std::uninitialized_copy(__first, __last, __result); }
template
inline _ForwardIterator
__uninitialized_move_a(_InputIterator __first, _InputIterator __last,
_ForwardIterator __result, _Allocator& __alloc)
{
return std::__uninitialized_copy_a(_GLIBCXX_MAKE_MOVE_ITERATOR(__first),
_GLIBCXX_MAKE_MOVE_ITERATOR(__last),
__result, __alloc);
}
template
inline _ForwardIterator
__uninitialized_move_if_noexcept_a(_InputIterator __first,
_InputIterator __last,
_ForwardIterator __result,
_Allocator& __alloc)
{
return std::__uninitialized_copy_a
(_GLIBCXX_MAKE_MOVE_IF_NOEXCEPT_ITERATOR(__first),
_GLIBCXX_MAKE_MOVE_IF_NOEXCEPT_ITERATOR(__last), __result, __alloc);
}
template
void
__uninitialized_fill_a(_ForwardIterator __first, _ForwardIterator __last,
const _Tp& __x, _Allocator& __alloc)
{
_ForwardIterator __cur = __first;
__try
{
typedef __gnu_cxx::__alloc_traits<_Allocator> __traits;
for (; __cur != __last; ++__cur)
__traits::construct(__alloc, std::__addressof(*__cur), __x);
}
__catch(...)
{
std::_Destroy(__first, __cur, __alloc);
__throw_exception_again;
}
}
template
inline void
__uninitialized_fill_a(_ForwardIterator __first, _ForwardIterator __last,
const _Tp& __x, allocator<_Tp2>&)
{ std::uninitialized_fill(__first, __last, __x); }
template
_ForwardIterator
__uninitialized_fill_n_a(_ForwardIterator __first, _Size __n,
const _Tp& __x, _Allocator& __alloc)
{
_ForwardIterator __cur = __first;
__try
{
typedef __gnu_cxx::__alloc_traits<_Allocator> __traits;
for (; __n > 0; --__n, ++__cur)
__traits::construct(__alloc, std::__addressof(*__cur), __x);
return __cur;
}
__catch(...)
{
std::_Destroy(__first, __cur, __alloc);
__throw_exception_again;
}
}
template
inline _ForwardIterator
__uninitialized_fill_n_a(_ForwardIterator __first, _Size __n,
const _Tp& __x, allocator<_Tp2>&)
{ return std::uninitialized_fill_n(__first, __n, __x); }
// Extensions: __uninitialized_copy_move, __uninitialized_move_copy,
// __uninitialized_fill_move, __uninitialized_move_fill.
// All of these algorithms take a user-supplied allocator, which is used
// for construction and destruction.
// __uninitialized_copy_move
// Copies [first1, last1) into [result, result + (last1 - first1)), and
// move [first2, last2) into
// [result, result + (last1 - first1) + (last2 - first2)).
template
inline _ForwardIterator
__uninitialized_copy_move(_InputIterator1 __first1,
_InputIterator1 __last1,
_InputIterator2 __first2,
_InputIterator2 __last2,
_ForwardIterator __result,
_Allocator& __alloc)
{
_ForwardIterator __mid = std::__uninitialized_copy_a(__first1, __last1,
__result,
__alloc);
__try
{
return std::__uninitialized_move_a(__first2, __last2, __mid, __alloc);
}
__catch(...)
{
std::_Destroy(__result, __mid, __alloc);
__throw_exception_again;
}
}
// __uninitialized_move_copy
// Moves [first1, last1) into [result, result + (last1 - first1)), and
// copies [first2, last2) into
// [result, result + (last1 - first1) + (last2 - first2)).
template
inline _ForwardIterator
__uninitialized_move_copy(_InputIterator1 __first1,
_InputIterator1 __last1,
_InputIterator2 __first2,
_InputIterator2 __last2,
_ForwardIterator __result,
_Allocator& __alloc)
{
_ForwardIterator __mid = std::__uninitialized_move_a(__first1, __last1,
__result,
__alloc);
__try
{
return std::__uninitialized_copy_a(__first2, __last2, __mid, __alloc);
}
__catch(...)
{
std::_Destroy(__result, __mid, __alloc);
__throw_exception_again;
}
}
// __uninitialized_fill_move
// Fills [result, mid) with x, and moves [first, last) into
// [mid, mid + (last - first)).
template
inline _ForwardIterator
__uninitialized_fill_move(_ForwardIterator __result, _ForwardIterator __mid,
const _Tp& __x, _InputIterator __first,
_InputIterator __last, _Allocator& __alloc)
{
std::__uninitialized_fill_a(__result, __mid, __x, __alloc);
__try
{
return std::__uninitialized_move_a(__first, __last, __mid, __alloc);
}
__catch(...)
{
std::_Destroy(__result, __mid, __alloc);
__throw_exception_again;
}
}
// __uninitialized_move_fill
// Moves [first1, last1) into [first2, first2 + (last1 - first1)), and
// fills [first2 + (last1 - first1), last2) with x.
template
inline void
__uninitialized_move_fill(_InputIterator __first1, _InputIterator __last1,
_ForwardIterator __first2,
_ForwardIterator __last2, const _Tp& __x,
_Allocator& __alloc)
{
_ForwardIterator __mid2 = std::__uninitialized_move_a(__first1, __last1,
__first2,
__alloc);
__try
{
std::__uninitialized_fill_a(__mid2, __last2, __x, __alloc);
}
__catch(...)
{
std::_Destroy(__first2, __mid2, __alloc);
__throw_exception_again;
}
}
#if __cplusplus >= 201103L
// Extensions: __uninitialized_default, __uninitialized_default_n,
// __uninitialized_default_a, __uninitialized_default_n_a.
template
struct __uninitialized_default_1
{
template
static void
__uninit_default(_ForwardIterator __first, _ForwardIterator __last)
{
_ForwardIterator __cur = __first;
__try
{
for (; __cur != __last; ++__cur)
std::_Construct(std::__addressof(*__cur));
}
__catch(...)
{
std::_Destroy(__first, __cur);
__throw_exception_again;
}
}
};
template<>
struct __uninitialized_default_1
{
template
static void
__uninit_default(_ForwardIterator __first, _ForwardIterator __last)
{
typedef typename iterator_traits<_ForwardIterator>::value_type
_ValueType;
std::fill(__first, __last, _ValueType());
}
};
template
struct __uninitialized_default_n_1
{
template
static _ForwardIterator
__uninit_default_n(_ForwardIterator __first, _Size __n)
{
_ForwardIterator __cur = __first;
__try
{
for (; __n > 0; --__n, ++__cur)
std::_Construct(std::__addressof(*__cur));
return __cur;
}
__catch(...)
{
std::_Destroy(__first, __cur);
__throw_exception_again;
}
}
};
template<>
struct __uninitialized_default_n_1
{
template
static _ForwardIterator
__uninit_default_n(_ForwardIterator __first, _Size __n)
{
typedef typename iterator_traits<_ForwardIterator>::value_type
_ValueType;
return std::fill_n(__first, __n, _ValueType());
}
};
// __uninitialized_default
// Fills [first, last) with std::distance(first, last) default
// constructed value_types(s).
template
inline void
__uninitialized_default(_ForwardIterator __first,
_ForwardIterator __last)
{
typedef typename iterator_traits<_ForwardIterator>::value_type
_ValueType;
// trivial types can have deleted assignment
const bool __assignable = is_copy_assignable<_ValueType>::value;
std::__uninitialized_default_1<__is_trivial(_ValueType)
&& __assignable>::
__uninit_default(__first, __last);
}
// __uninitialized_default_n
// Fills [first, first + n) with n default constructed value_type(s).
template
inline _ForwardIterator
__uninitialized_default_n(_ForwardIterator __first, _Size __n)
{
typedef typename iterator_traits<_ForwardIterator>::value_type
_ValueType;
// trivial types can have deleted assignment
const bool __assignable = is_copy_assignable<_ValueType>::value;
return __uninitialized_default_n_1<__is_trivial(_ValueType)
&& __assignable>::
__uninit_default_n(__first, __n);
}
// __uninitialized_default_a
// Fills [first, last) with std::distance(first, last) default
// constructed value_types(s), constructed with the allocator alloc.
template
void
__uninitialized_default_a(_ForwardIterator __first,
_ForwardIterator __last,
_Allocator& __alloc)
{
_ForwardIterator __cur = __first;
__try
{
typedef __gnu_cxx::__alloc_traits<_Allocator> __traits;
for (; __cur != __last; ++__cur)
__traits::construct(__alloc, std::__addressof(*__cur));
}
__catch(...)
{
std::_Destroy(__first, __cur, __alloc);
__throw_exception_again;
}
}
template
inline void
__uninitialized_default_a(_ForwardIterator __first,
_ForwardIterator __last,
allocator<_Tp>&)
{ std::__uninitialized_default(__first, __last); }
// __uninitialized_default_n_a
// Fills [first, first + n) with n default constructed value_types(s),
// constructed with the allocator alloc.
template
_ForwardIterator
__uninitialized_default_n_a(_ForwardIterator __first, _Size __n,
_Allocator& __alloc)
{
_ForwardIterator __cur = __first;
__try
{
typedef __gnu_cxx::__alloc_traits<_Allocator> __traits;
for (; __n > 0; --__n, ++__cur)
__traits::construct(__alloc, std::__addressof(*__cur));
return __cur;
}
__catch(...)
{
std::_Destroy(__first, __cur, __alloc);
__throw_exception_again;
}
}
template
inline _ForwardIterator
__uninitialized_default_n_a(_ForwardIterator __first, _Size __n,
allocator<_Tp>&)
{ return std::__uninitialized_default_n(__first, __n); }
template
_ForwardIterator
__uninitialized_copy_n(_InputIterator __first, _Size __n,
_ForwardIterator __result, input_iterator_tag)
{
_ForwardIterator __cur = __result;
__try
{
for (; __n > 0; --__n, ++__first, ++__cur)
std::_Construct(std::__addressof(*__cur), *__first);
return __cur;
}
__catch(...)
{
std::_Destroy(__result, __cur);
__throw_exception_again;
}
}
template
inline _ForwardIterator
__uninitialized_copy_n(_RandomAccessIterator __first, _Size __n,
_ForwardIterator __result,
random_access_iterator_tag)
{ return std::uninitialized_copy(__first, __first + __n, __result); }
/**
* @brief Copies the range [first,first+n) into result.
* @param __first An input iterator.
* @param __n The number of elements to copy.
* @param __result An output iterator.
* @return __result + __n
*
* Like copy_n(), but does not require an initialized output range.
*/
template
inline _ForwardIterator
uninitialized_copy_n(_InputIterator __first, _Size __n,
_ForwardIterator __result)
{ return std::__uninitialized_copy_n(__first, __n, __result,
std::__iterator_category(__first)); }
#endif
