HumanRender/human_render/Ipc/libipc/utility/pimpl.h
2024-12-22 23:24:02 +08:00

65 lines
1.6 KiB
C++

#pragma once
#include <new>
#include <utility>
#include "libipc/platform/detail.h"
#include "libipc/utility/concept.h"
#include "libipc/pool_alloc.h"
namespace ipc {
// pimpl small object optimization helpers
template <typename T, typename R = T*>
using IsImplComfortable = ipc::require<(sizeof(T) <= sizeof(T*)), R>;
template <typename T, typename R = T*>
using IsImplUncomfortable = ipc::require<(sizeof(T) > sizeof(T*)), R>;
template <typename T, typename... P>
IPC_CONSTEXPR_ auto make_impl(P&&... params) -> IsImplComfortable<T> {
T* buf {};
::new (&buf) T { std::forward<P>(params)... };
return buf;
}
template <typename T>
IPC_CONSTEXPR_ auto impl(T* const (& p)) -> IsImplComfortable<T> {
return reinterpret_cast<T*>(&const_cast<char &>(reinterpret_cast<char const &>(p)));
}
template <typename T>
IPC_CONSTEXPR_ auto clear_impl(T* p) -> IsImplComfortable<T, void> {
if (p != nullptr) impl(p)->~T();
}
template <typename T, typename... P>
IPC_CONSTEXPR_ auto make_impl(P&&... params) -> IsImplUncomfortable<T> {
return mem::alloc<T>(std::forward<P>(params)...);
}
template <typename T>
IPC_CONSTEXPR_ auto clear_impl(T* p) -> IsImplUncomfortable<T, void> {
mem::free(p);
}
template <typename T>
IPC_CONSTEXPR_ auto impl(T* const (& p)) -> IsImplUncomfortable<T> {
return p;
}
template <typename T>
struct pimpl {
template <typename... P>
IPC_CONSTEXPR_ static T* make(P&&... params) {
return make_impl<T>(std::forward<P>(params)...);
}
IPC_CONSTEXPR_ void clear() {
clear_impl(static_cast<T*>(const_cast<pimpl*>(this)));
}
};
} // namespace ipc