// Raw memory manipulators -*- C++ -*-
-// Copyright (C) 2001-2019 Free Software Foundation, Inc.
+// Copyright (C) 2001-2021 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
#define _STL_UNINITIALIZED_H 1
#if __cplusplus > 201402L
-#include <utility>
+#include <bits/stl_pair.h>
#endif
#if __cplusplus >= 201103L
#include <type_traits>
#endif
+#include <ext/alloc_traits.h>
+
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
+ /** @addtogroup memory
+ * @{
+ */
+
+ /// @cond undocumented
+
template<bool _TrivialValueTypes>
struct __uninitialized_copy
{
{ return std::copy(__first, __last, __result); }
};
+ /// @endcond
+
/**
* @brief Copies the range [first,last) into result.
* @param __first An input iterator.
#if __cplusplus < 201103L
const bool __assignable = true;
#else
- // trivial types can have deleted assignment
+ // Trivial types can have deleted copy constructor, but the std::copy
+ // optimization that uses memmove would happily "copy" them anyway.
+ static_assert(is_constructible<_ValueType2, decltype(*__first)>::value,
+ "result type must be constructible from value type of input range");
+
typedef typename iterator_traits<_InputIterator>::reference _RefType1;
typedef typename iterator_traits<_ForwardIterator>::reference _RefType2;
+ // Trivial types can have deleted assignment, so using std::copy
+ // would be ill-formed. Require assignability before using std::copy:
const bool __assignable = is_assignable<_RefType2, _RefType1>::value;
#endif
__uninit_copy(__first, __last, __result);
}
+ /// @cond undocumented
template<bool _TrivialValueType>
struct __uninitialized_fill
{ std::fill(__first, __last, __x); }
};
+ /// @endcond
+
/**
* @brief Copies the value x into the range [first,last).
* @param __first An input iterator.
#if __cplusplus < 201103L
const bool __assignable = true;
#else
- // trivial types can have deleted assignment
+ // Trivial types can have deleted copy constructor, but the std::fill
+ // optimization that uses memmove would happily "copy" them anyway.
+ static_assert(is_constructible<_ValueType, const _Tp&>::value,
+ "result type must be constructible from input type");
+
+ // Trivial types can have deleted assignment, so using std::fill
+ // would be ill-formed. Require assignability before using std::fill:
const bool __assignable = is_copy_assignable<_ValueType>::value;
#endif
__uninit_fill(__first, __last, __x);
}
+ /// @cond undocumented
template<bool _TrivialValueType>
struct __uninitialized_fill_n
{ return std::fill_n(__first, __n, __x); }
};
+ /// @endcond
+
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// DR 1339. uninitialized_fill_n should return the end of its range
/**
{
typedef typename iterator_traits<_ForwardIterator>::value_type
_ValueType;
+
+ // Trivial types do not need a constructor to begin their lifetime,
+ // so try to use std::fill_n to benefit from its memmove optimization.
+ // For arbitrary class types and floating point types we can't assume
+ // that __n > 0 and std::__size_to_integer(__n) > 0 are equivalent,
+ // so only use std::fill_n when _Size is already an integral type.
#if __cplusplus < 201103L
- const bool __assignable = true;
+ const bool __can_fill = __is_integer<_Size>::__value;
#else
- // trivial types can have deleted assignment
- const bool __assignable = is_copy_assignable<_ValueType>::value;
+ // Trivial types can have deleted copy constructor, but the std::fill_n
+ // optimization that uses memmove would happily "copy" them anyway.
+ static_assert(is_constructible<_ValueType, const _Tp&>::value,
+ "result type must be constructible from input type");
+
+ // Trivial types can have deleted assignment, so using std::fill_n
+ // would be ill-formed. Require assignability before using std::fill_n:
+ constexpr bool __can_fill
+ = __and_<is_integral<_Size>, is_copy_assignable<_ValueType>>::value;
#endif
- return __uninitialized_fill_n<__is_trivial(_ValueType) && __assignable>::
+ return __uninitialized_fill_n<__is_trivial(_ValueType) && __can_fill>::
__uninit_fill_n(__first, __n, __x);
}
+ /// @cond undocumented
+
// 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
}
}
+ /// @endcond
+
#if __cplusplus >= 201103L
+ /// @cond undocumented
+
// Extensions: __uninitialized_default, __uninitialized_default_n,
// __uninitialized_default_a, __uninitialized_default_n_a.
static void
__uninit_default(_ForwardIterator __first, _ForwardIterator __last)
{
- typedef typename iterator_traits<_ForwardIterator>::value_type
- _ValueType;
-
- std::fill(__first, __last, _ValueType());
+ if (__first == __last)
+ return;
+
+ typename iterator_traits<_ForwardIterator>::value_type* __val
+ = std::__addressof(*__first);
+ std::_Construct(__val);
+ if (++__first != __last)
+ std::fill(__first, __last, *__val);
}
};
static _ForwardIterator
__uninit_default_n(_ForwardIterator __first, _Size __n)
{
- typedef typename iterator_traits<_ForwardIterator>::value_type
- _ValueType;
-
- return std::fill_n(__first, __n, _ValueType());
+ if (__n > 0)
+ {
+ typename iterator_traits<_ForwardIterator>::value_type* __val
+ = std::__addressof(*__first);
+ std::_Construct(__val);
+ ++__first;
+ __first = std::fill_n(__first, __n - 1, *__val);
+ }
+ return __first;
}
};
// __uninitialized_default
- // Fills [first, last) with std::distance(first, last) default
- // constructed value_types(s).
+ // Fills [first, last) with value-initialized value_types.
template<typename _ForwardIterator>
inline void
__uninitialized_default(_ForwardIterator __first,
}
// __uninitialized_default_n
- // Fills [first, first + n) with n default constructed value_type(s).
+ // Fills [first, first + n) with value-initialized value_types.
template<typename _ForwardIterator, typename _Size>
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;
+ // See uninitialized_fill_n for the conditions for using std::fill_n.
+ constexpr bool __can_fill
+ = __and_<is_integral<_Size>, is_copy_assignable<_ValueType>>::value;
return __uninitialized_default_n_1<__is_trivial(_ValueType)
- && __assignable>::
+ && __can_fill>::
__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.
+ // Fills [first, last) with value_types constructed by the allocator
+ // alloc, with no arguments passed to the construct call.
template<typename _ForwardIterator, typename _Allocator>
void
__uninitialized_default_a(_ForwardIterator __first,
// __uninitialized_default_n_a
- // Fills [first, first + n) with n default constructed value_types(s),
- // constructed with the allocator alloc.
+ // Fills [first, first + n) with value_types constructed by the allocator
+ // alloc, with no arguments passed to the construct call.
template<typename _ForwardIterator, typename _Size, typename _Allocator>
_ForwardIterator
__uninitialized_default_n_a(_ForwardIterator __first, _Size __n,
}
}
+ // __uninitialized_default_n_a specialization for std::allocator,
+ // which ignores the allocator and value-initializes the elements.
template<typename _ForwardIterator, typename _Size, typename _Tp>
inline _ForwardIterator
__uninitialized_default_n_a(_ForwardIterator __first, _Size __n,
};
// __uninitialized_default_novalue
- // Fills [first, last) with std::distance(first, last) default-initialized
- // value_types(s).
+ // Fills [first, last) with default-initialized value_types.
template<typename _ForwardIterator>
inline void
__uninitialized_default_novalue(_ForwardIterator __first,
__uninit_default_novalue(__first, __last);
}
- // __uninitialized_default_n
- // Fills [first, first + n) with n default-initialized value_type(s).
+ // __uninitialized_default_novalue_n
+ // Fills [first, first + n) with default-initialized value_types.
template<typename _ForwardIterator, typename _Size>
inline _ForwardIterator
__uninitialized_default_novalue_n(_ForwardIterator __first, _Size __n)
return {__first_res, __second_res};
}
+ /// @endcond
+
/**
* @brief Copies the range [first,first+n) into result.
* @param __first An input iterator.
{ return std::__uninitialized_copy_n(__first, __n, __result,
std::__iterator_category(__first)); }
+ /// @cond undocumented
template<typename _InputIterator, typename _Size, typename _ForwardIterator>
inline pair<_InputIterator, _ForwardIterator>
__uninitialized_copy_n_pair(_InputIterator __first, _Size __n,
std::__uninitialized_copy_n_pair(__first, __n, __result,
std::__iterator_category(__first));
}
-
+ /// @endcond
#endif
#if __cplusplus >= 201703L
# define __cpp_lib_raw_memory_algorithms 201606L
+ /**
+ * @brief Default-initializes objects in the range [first,last).
+ * @param __first A forward iterator.
+ * @param __last A forward iterator.
+ */
template <typename _ForwardIterator>
inline void
uninitialized_default_construct(_ForwardIterator __first,
__uninitialized_default_novalue(__first, __last);
}
+ /**
+ * @brief Default-initializes objects in the range [first,first+count).
+ * @param __first A forward iterator.
+ * @param __count The number of objects to construct.
+ * @return __first + __count
+ */
template <typename _ForwardIterator, typename _Size>
inline _ForwardIterator
uninitialized_default_construct_n(_ForwardIterator __first, _Size __count)
return __uninitialized_default_novalue_n(__first, __count);
}
+ /**
+ * @brief Value-initializes objects in the range [first,last).
+ * @param __first A forward iterator.
+ * @param __last A forward iterator.
+ */
template <typename _ForwardIterator>
inline void
uninitialized_value_construct(_ForwardIterator __first,
return __uninitialized_default(__first, __last);
}
+ /**
+ * @brief Value-initializes objects in the range [first,first+count).
+ * @param __first A forward iterator.
+ * @param __count The number of objects to construct.
+ * @return __result + __count
+ */
template <typename _ForwardIterator, typename _Size>
inline _ForwardIterator
uninitialized_value_construct_n(_ForwardIterator __first, _Size __count)
return __uninitialized_default_n(__first, __count);
}
+ /**
+ * @brief Move-construct from 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)
+ */
template <typename _InputIterator, typename _ForwardIterator>
inline _ForwardIterator
uninitialized_move(_InputIterator __first, _InputIterator __last,
_GLIBCXX_MAKE_MOVE_ITERATOR(__last), __result);
}
+ /**
+ * @brief Move-construct from the range [first,first+count) into result.
+ * @param __first An input iterator.
+ * @param __count The number of objects to initialize.
+ * @param __result An output iterator.
+ * @return __result + __count
+ */
template <typename _InputIterator, typename _Size, typename _ForwardIterator>
inline pair<_InputIterator, _ForwardIterator>
uninitialized_move_n(_InputIterator __first, _Size __count,
#endif // C++17
#if __cplusplus >= 201103L
+ /// @cond undocumented
+
template<typename _Tp, typename _Up, typename _Allocator>
inline void
- __relocate_object_a(_Tp* __dest, _Up* __orig, _Allocator& __alloc)
+ __relocate_object_a(_Tp* __restrict __dest, _Up* __restrict __orig,
+ _Allocator& __alloc)
noexcept(noexcept(std::allocator_traits<_Allocator>::construct(__alloc,
__dest, std::move(*__orig)))
&& noexcept(std::allocator_traits<_Allocator>::destroy(
}
// This class may be specialized for specific types.
+ // Also known as is_trivially_relocatable.
template<typename _Tp, typename = void>
- struct __is_trivially_relocatable
+ struct __is_bitwise_relocatable
: is_trivial<_Tp> { };
template <typename _Tp, typename _Up>
- inline __enable_if_t<std::__is_trivially_relocatable<_Tp>::value, _Tp*>
+ inline __enable_if_t<std::__is_bitwise_relocatable<_Tp>::value, _Tp*>
__relocate_a_1(_Tp* __first, _Tp* __last,
- _Tp* __result, allocator<_Up>& __alloc) noexcept
+ _Tp* __result, allocator<_Up>&) noexcept
{
ptrdiff_t __count = __last - __first;
if (__count > 0)
_ValueType;
typedef typename iterator_traits<_ForwardIterator>::value_type
_ValueType2;
- static_assert(std::is_same<_ValueType, _ValueType2>::value);
+ static_assert(std::is_same<_ValueType, _ValueType2>::value,
+ "relocation is only possible for values of the same type");
_ForwardIterator __cur = __result;
for (; __first != __last; ++__first, (void)++__cur)
std::__relocate_object_a(std::__addressof(*__cur),
std::__niter_base(__last),
std::__niter_base(__result), __alloc);
}
+
+ /// @endcond
#endif
+ // @} group memory
+
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace