libcxx/include/__memory/destruct_n.h

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #ifndef _LIBCPP___MEMORY_DESTRUCT_N_H
  10 #define _LIBCPP___MEMORY_DESTRUCT_N_H
  11
  12 #include <__config>
  13 #include <__type_traits/integral_constant.h>
  14 #include <__type_traits/is_trivially_destructible.h>
  15 #include <cstddef>
  16
  17 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  18 #  pragma GCC system_header
  19 #endif
  20
  21 _LIBCPP_BEGIN_NAMESPACE_STD
  22
  23 struct __destruct_n
  24 {
  25 private:
  26     size_t __size_;
  27
  28     template <class _Tp>
  29     _LIBCPP_INLINE_VISIBILITY void __process(_Tp* __p, false_type) _NOEXCEPT
  30         {for (size_t __i = 0; __i < __size_; ++__i, ++__p) __p->~_Tp();}
  31
  32     template <class _Tp>
  33     _LIBCPP_INLINE_VISIBILITY void __process(_Tp*, true_type) _NOEXCEPT
  34         {}
  35
  36     _LIBCPP_INLINE_VISIBILITY void __incr(false_type) _NOEXCEPT
  37         {++__size_;}
  38     _LIBCPP_INLINE_VISIBILITY void __incr(true_type) _NOEXCEPT
  39         {}
  40
  41     _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, false_type) _NOEXCEPT
  42         {__size_ = __s;}
  43     _LIBCPP_INLINE_VISIBILITY void __set(size_t, true_type) _NOEXCEPT
  44         {}
  45 public:
  46     _LIBCPP_INLINE_VISIBILITY explicit __destruct_n(size_t __s) _NOEXCEPT
  47         : __size_(__s) {}
  48
  49     template <class _Tp>
  50     _LIBCPP_INLINE_VISIBILITY void __incr() _NOEXCEPT
  51         {__incr(integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
  52
  53     template <class _Tp>
  54     _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, _Tp*) _NOEXCEPT
  55         {__set(__s, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
  56
  57     template <class _Tp>
  58     _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __p) _NOEXCEPT
  59         {__process(__p, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
  60 };
  61
  62 _LIBCPP_END_NAMESPACE_STD
  63
  64 #endif // _LIBCPP___MEMORY_DESTRUCT_N_H