darling-libcxx/include/__sso_allocator
Chandler Carruth 7c3769df62 Update more file headers across all of the LLVM projects in the monorepo
to reflect the new license. These used slightly different spellings that
defeated my regular expressions.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@351648 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-19 10:56:40 +00:00

77 lines
2.5 KiB
C++

// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP___SSO_ALLOCATOR
#define _LIBCPP___SSO_ALLOCATOR
#include <__config>
#include <type_traits>
#include <new>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#pragma GCC system_header
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
template <class _Tp, size_t _Np> class _LIBCPP_HIDDEN __sso_allocator;
template <size_t _Np>
class _LIBCPP_HIDDEN __sso_allocator<void, _Np>
{
public:
typedef const void* const_pointer;
typedef void value_type;
};
template <class _Tp, size_t _Np>
class _LIBCPP_HIDDEN __sso_allocator
{
typename aligned_storage<sizeof(_Tp) * _Np>::type buf_;
bool __allocated_;
public:
typedef size_t size_type;
typedef _Tp* pointer;
typedef _Tp value_type;
_LIBCPP_INLINE_VISIBILITY __sso_allocator() throw() : __allocated_(false) {}
_LIBCPP_INLINE_VISIBILITY __sso_allocator(const __sso_allocator&) throw() : __allocated_(false) {}
template <class _Up> _LIBCPP_INLINE_VISIBILITY __sso_allocator(const __sso_allocator<_Up, _Np>&) throw()
: __allocated_(false) {}
private:
__sso_allocator& operator=(const __sso_allocator&);
public:
_LIBCPP_INLINE_VISIBILITY pointer allocate(size_type __n, typename __sso_allocator<void, _Np>::const_pointer = 0)
{
if (!__allocated_ && __n <= _Np)
{
__allocated_ = true;
return (pointer)&buf_;
}
return static_cast<pointer>(_VSTD::__libcpp_allocate(__n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp)));
}
_LIBCPP_INLINE_VISIBILITY void deallocate(pointer __p, size_type __n)
{
if (__p == (pointer)&buf_)
__allocated_ = false;
else
_VSTD::__libcpp_deallocate(__p, __n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));
}
_LIBCPP_INLINE_VISIBILITY size_type max_size() const throw() {return size_type(~0) / sizeof(_Tp);}
_LIBCPP_INLINE_VISIBILITY
bool operator==(__sso_allocator& __a) const {return &buf_ == &__a.buf_;}
_LIBCPP_INLINE_VISIBILITY
bool operator!=(__sso_allocator& __a) const {return &buf_ != &__a.buf_;}
};
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___SSO_ALLOCATOR