std::experimental::reflect::Object

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Experimental
Technical Specification
Filesystem library (filesystem TS)
Library fundamentals (library fundamentals TS)
Library fundamentals 2 (library fundamentals TS v2)
Library fundamentals 3 (library fundamentals TS v3)
Extensions for parallelism (parallelism TS)
Extensions for parallelism 2 (parallelism TS v2)
Extensions for concurrency (concurrency TS)
Extensions for concurrency 2 (concurrency TS v2)
Concepts (concepts TS)
Ranges (ranges TS)
Reflection (reflection TS)
Mathematical special functions (special functions TR)
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Pattern Matching
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std::execution
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Extensions for reflection
Concepts
Meta-object operations
Variable
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Callable
Variable and Callable
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ParenthesizedExpression
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FunctionalConversion
Variable and Function
 
Defined in header <experimental/reflect>
template< class T >
concept Object = /* see below */;
(reflection TS)

The Object concept is satisfied if and only if T is a meta-object type.

Example

#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>; // error: int is not a meta-object type
}