libcruft-util/alloc/raw/null.hpp

79 lines
2.1 KiB
C++

/*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Copyright 2015 Danny Robson <danny@nerdcruft.net>
*/
#ifndef CRUFT_UTIL_ALLOC_RAW_NULL_HPP
#define CRUFT_UTIL_ALLOC_RAW_NULL_HPP
#include "../../view.hpp"
#include <cstddef>
namespace util::alloc::raw {
// allocator that always fails, throwing bad_alloc. deallocate will
// succeed with nullptr as with delete, but is undefined with other values
// (it is likely to at least assert).
class null {
public:
null () = default;
null (const null&) = delete;
null& operator= (const null&) = delete;
template <typename T>
util::view<T*>
allocate (size_t count)
{
return allocate<T> (count, alignof (T));
}
template <typename T>
util::view<T*>
allocate (size_t count, size_t align)
{
(void)count;
(void)align;
throw std::bad_alloc ();
}
template <typename T>
void
deallocate (util::view<T*> ptr)
{
(void)ptr;
CHECK_EQ (ptr.data (), static_cast<const void*> (nullptr));
}
util::view<std::byte*> data (void);
util::view<const std::byte*> data (void) const;
std::byte* begin (void);
const std::byte* begin (void) const;
std::byte* end (void);
const std::byte* end (void) const;
size_t offset (const void*) const;
void reset (void);
size_t capacity (void) const;
size_t used (void) const;
size_t remain (void) const;
};
}
#endif