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 <__cstddef/size_t.h>
  14 #include <__type_traits/integral_constant.h>
  15 #include <__type_traits/is_trivially_destructible.h>
  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 private:
  25   size_t __size_;
  26
  27   template <class _Tp>
  28   _LIBCPP_HIDE_FROM_ABI void __process(_Tp* __p, false_type) _NOEXCEPT {
  29     for (size_t __i = 0; __i < __size_; ++__i, ++__p)
  30       __p->~_Tp();
  31   }
  32
  33   template <class _Tp>
  34   _LIBCPP_HIDE_FROM_ABI void __process(_Tp*, true_type) _NOEXCEPT {}
  35
  36   _LIBCPP_HIDE_FROM_ABI void __incr(false_type) _NOEXCEPT { ++__size_; }
  37   _LIBCPP_HIDE_FROM_ABI void __incr(true_type) _NOEXCEPT {}
  38
  39   _LIBCPP_HIDE_FROM_ABI void __set(size_t __s, false_type) _NOEXCEPT { __size_ = __s; }
  40   _LIBCPP_HIDE_FROM_ABI void __set(size_t, true_type) _NOEXCEPT {}
  41
  42 public:
  43   _LIBCPP_HIDE_FROM_ABI explicit __destruct_n(size_t __s) _NOEXCEPT : __size_(__s) {}
  44
  45   template <class _Tp>
  46   _LIBCPP_HIDE_FROM_ABI void __incr() _NOEXCEPT {
  47     __incr(integral_constant<bool, is_trivially_destructible<_Tp>::value>());
  48   }
  49
  50   template <class _Tp>
  51   _LIBCPP_HIDE_FROM_ABI void __set(size_t __s, _Tp*) _NOEXCEPT {
  52     __set(__s, integral_constant<bool, is_trivially_destructible<_Tp>::value>());
  53   }
  54
  55   template <class _Tp>
  56   _LIBCPP_HIDE_FROM_ABI void operator()(_Tp* __p) _NOEXCEPT {
  57     __process(__p, integral_constant<bool, is_trivially_destructible<_Tp>::value>());
  58   }
  59 };
  60
  61 _LIBCPP_END_NAMESPACE_STD
  62
  63 #endif // _LIBCPP___MEMORY_DESTRUCT_N_H