zengine-old/engine/3rdparty/zlib/include/refl/detail/any.h

#pragma once
#include "type.h"
namespace refl {
	class UClass;
	//生命周期短，适用于传参，不建议保存数据
	//只能指向指针，引用=>指针，指针=>指针，T => T*,T的类型丢失
	struct Any {
	public:
		const void* ptr;
		const UClass* cls;
		constexpr Any(const void* ptr, const UClass* cls) : ptr(ptr), cls(cls) {
			//assert(cls->flag & CLASS_POINTER_FLAG);
		}
		constexpr Any() : ptr(nullptr), cls(nullptr) {}
		//右值=>右值压入栈，caller入栈地址
		//左值=>caller变量地址
		template<typename T>
		constexpr Any(T&& v) : ptr(&v), cls(&TypeInfo<args_type_t<T>*>::StaticClass) {
			if constexpr (std::is_same_v<args_type_t<T>, Any>) {
				ptr = v.ptr;
				cls = v.cls;
			}
		}
		template<typename T>
		constexpr Any(T* v) : ptr(v), cls(&TypeInfo<args_type_t<T>*>::StaticClass) {
			if constexpr (std::is_same_v<args_type_t<T>, Any>) {
				ptr = v->ptr;
				cls = v->cls;
			}
		}
		template<typename T>//参数 T* => T*
		constexpr inline T CastTo() const {
			if constexpr (std::is_pointer_v<T>) {
				return (T)ptr;
			}
			else if constexpr (std::is_reference_v<T>) {
				using RT = std::remove_reference_t<T>;
				return *(RT*)ptr;
			}
			else {
				return *(T*)ptr;
			}
		}
		bool Check(const UClass* toClass)const;
		constexpr bool IsValid() const{
			return cls != nullptr && ptr != nullptr;
		}
		constexpr int Size()const;
		constexpr const UClass* Parent()const;
		constexpr Any Change(const void* ptr)const {
			return {ptr, cls};
		}
	};
}