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std::experimental::reflect:: Object

From cppreference.net
C++
Experimental
Extensions for reflection
Concepts
Meta-object operations
Variable
FunctionParameter
Callable
Variable and Callable
Namespace and Callable
ParenthesizedExpression
FunctionCallExpression
FunctionalConversion
Variable and Function
定义于头文件 <experimental/reflect>
template < class T >
concept Object = /* 见下文 */ ;
(反射 TS)

当且仅当 T 为元对象类型时， Object 概念得到满足。

示例

运行此代码 
#include <experimental/reflect>
namespace reflect = std::experimental::reflect;
template<reflect::Object M>
struct meta_t {
    template<reflect::Object M1>
    friend constexpr bool operator==(meta_t, meta_t<M1>) noexcept
    {
        return reflect::reflects_same_v<M, M1>;
    }
    template<reflect::Object M1>
    friend constexpr bool operator!=(meta_t, meta_t<M1>) noexcept
    {
        return !reflect::reflects_same_v<M, M1>;
    }
};
template<reflect::Object M>
constexpr meta_t<M> meta{};
int main()
{
    static_assert(meta<reflexpr(int)> == meta<reflexpr(signed int)>, "");
    // meta<int>; // 错误：int 不是元对象类型
}