ab9f5d2067
The former was deprecated with C++14. According to the C++11 and C++17 standards, both files are identical. Signed-off-by: Rosen Penev <rosenp@gmail.com>
130 lines
2.9 KiB
C++
130 lines
2.9 KiB
C++
/*
|
|
* Copyright (C) 2013-2017 Max Kellermann <max.kellermann@gmail.com>
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
*
|
|
* - Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
*
|
|
* - Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the
|
|
* distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
|
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
|
* FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
|
|
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
|
|
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
|
|
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
|
|
* OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
#ifndef MANUAL_HXX
|
|
#define MANUAL_HXX
|
|
|
|
#include <cassert>
|
|
#include <new>
|
|
#include <utility>
|
|
|
|
#if defined(__GNUC__) || defined(__clang__)
|
|
#pragma GCC diagnostic push
|
|
#pragma GCC diagnostic ignored "-Wstrict-aliasing"
|
|
#endif
|
|
|
|
/**
|
|
* Container for an object that gets constructed and destructed
|
|
* manually. The object is constructed in-place, and therefore
|
|
* without allocation overhead. It can be constructed and destructed
|
|
* repeatedly.
|
|
*/
|
|
template<class T>
|
|
class Manual {
|
|
alignas(T)
|
|
char data[sizeof(T)];
|
|
|
|
#ifndef NDEBUG
|
|
bool initialized = false;
|
|
#endif
|
|
|
|
public:
|
|
#ifndef NDEBUG
|
|
~Manual() {
|
|
assert(!initialized);
|
|
}
|
|
#endif
|
|
|
|
/**
|
|
* Cast a value reference to the containing Manual instance.
|
|
*/
|
|
static constexpr Manual<T> &Cast(T &value) {
|
|
return reinterpret_cast<Manual<T> &>(value);
|
|
}
|
|
|
|
template<typename... Args>
|
|
void Construct(Args&&... args) {
|
|
assert(!initialized);
|
|
|
|
void *p = data;
|
|
new(p) T(std::forward<Args>(args)...);
|
|
|
|
#ifndef NDEBUG
|
|
initialized = true;
|
|
#endif
|
|
}
|
|
|
|
void Destruct() {
|
|
assert(initialized);
|
|
|
|
T &t = Get();
|
|
t.T::~T();
|
|
|
|
#ifndef NDEBUG
|
|
initialized = false;
|
|
#endif
|
|
}
|
|
|
|
T &Get() {
|
|
assert(initialized);
|
|
|
|
void *p = static_cast<void *>(data);
|
|
return *static_cast<T *>(p);
|
|
}
|
|
|
|
const T &Get() const {
|
|
assert(initialized);
|
|
|
|
const void *p = static_cast<const void *>(data);
|
|
return *static_cast<const T *>(p);
|
|
}
|
|
|
|
operator T &() {
|
|
return Get();
|
|
}
|
|
|
|
operator const T &() const {
|
|
return Get();
|
|
}
|
|
|
|
T *operator->() {
|
|
return &Get();
|
|
}
|
|
|
|
const T *operator->() const {
|
|
return &Get();
|
|
}
|
|
};
|
|
|
|
#if defined(__GNUC__) || defined(__clang__)
|
|
#pragma GCC diagnostic pop
|
|
#endif
|
|
|
|
#endif
|