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#pragma once
#include <memory>
namespace OpenVic {
// Based on https://github.com/think-cell/think-cell-library/blob/b9c84dd7fc926fad80829ed49705fa51afe36e87/tc/base/ref.h
// Boost Software License - Version 1.0 - August 17th, 2003
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
union AnyRef {
// Any pointer to function can be converted to a pointer to a different function type. Calling the
// function through a pointer to a different function type is undefined, but converting such pointer
// back to pointer to the original function type yields the pointer to the original function.
// https://en.cppreference.com/w/cpp/language/reinterpret_cast
template<typename T>
[[nodiscard]] static constexpr T* as_mutable_ptr(T const* pt) noexcept {
return const_cast<T*>(pt);
}
template<typename RefT>
explicit AnyRef(RefT& ref) noexcept : m_pvRef(std::addressof(ref)) {}
template<typename RefT>
requires std::is_function<RefT>::value
explicit AnyRef(RefT& ref) noexcept : m_fpvRef(reinterpret_cast<void (*)()>(std::addressof(ref))) {}
template<typename RefT> // may be const and/or volatile
RefT& get_ref() const& noexcept {
static_assert(!std::is_reference<RefT>::value);
if constexpr (std::is_function<RefT>::value) {
return *reinterpret_cast<RefT*>(m_fpvRef);
} else {
return *static_cast<RefT*>(as_mutable_ptr(m_pvRef));
}
}
void const* m_pvRef;
void (*m_fpvRef)();
};
}
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