ext-boost/boost/core/noinit_adaptor.hpp
2020-02-10 12:31:57 -04:00

113 lines
2.4 KiB
C++

/*
Copyright 2019 Glen Joseph Fernandes
(glenjofe@gmail.com)
Distributed under the Boost Software License, Version 1.0.
(http://www.boost.org/LICENSE_1_0.txt)
*/
#ifndef BOOST_CORE_NOINIT_ADAPTOR_HPP
#define BOOST_CORE_NOINIT_ADAPTOR_HPP
#include <boost/config.hpp>
#if !defined(BOOST_NO_CXX11_ALLOCATOR)
#include <memory>
#endif
#include <new>
#if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
#include <utility>
#endif
namespace boost {
template<class A>
struct noinit_adaptor
: A {
template<class U>
struct rebind {
#if !defined(BOOST_NO_CXX11_ALLOCATOR)
typedef noinit_adaptor<typename std::allocator_traits<A>::template
rebind_alloc<U> > other;
#else
typedef noinit_adaptor<typename A::template rebind<U>::other> other;
#endif
};
noinit_adaptor()
: A() { }
#if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
template<class U>
noinit_adaptor(U&& u) BOOST_NOEXCEPT
: A(std::forward<U>(u)) { }
#else
template<class U>
noinit_adaptor(const U& u) BOOST_NOEXCEPT
: A(u) { }
#endif
template<class U>
noinit_adaptor(const noinit_adaptor<U>& u) BOOST_NOEXCEPT
: A(static_cast<const U&>(u)) { }
template<class U>
void construct(U* p) {
::new((void*)p) U;
}
#if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
#if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
template<class U, class V, class... Args>
void construct(U* p, V&& v, Args&&... args) {
::new((void*)p) U(std::forward<V>(v), std::forward<Args>(args)...);
}
#else
template<class U, class V>
void construct(U* p, V&& v) {
::new((void*)p) U(std::forward<V>(v));
}
#endif
#else
template<class U, class V>
void construct(U* p, const V& v) {
::new((void*)p) U(v);
}
template<class U, class V>
void construct(U* p, V& v) {
::new((void*)p) U(v);
}
#endif
template<class U>
void destroy(U* p) {
p->~U();
}
};
template<class T, class U>
inline bool
operator==(const noinit_adaptor<T>& lhs,
const noinit_adaptor<U>& rhs) BOOST_NOEXCEPT
{
return static_cast<const T&>(lhs) == static_cast<const U&>(rhs);
}
template<class T, class U>
inline bool
operator!=(const noinit_adaptor<T>& lhs,
const noinit_adaptor<U>& rhs) BOOST_NOEXCEPT
{
return !(lhs == rhs);
}
template<class A>
inline noinit_adaptor<A>
noinit_adapt(const A& a) BOOST_NOEXCEPT
{
return noinit_adaptor<A>(a);
}
} /* boost */
#endif