cpp_modern/GeneralSnippets/Reflection/Reflection_03.txt at master · pelocpp/cpp_modern · GitHub

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// =====================================================================================
// Reflection_03.txt
// =====================================================================================

#include <meta>
#include <print>

namespace demo
{
    struct S
    {
      int x;
    };

    enum class E: uint8_t
    {
        A = 1,
        B = 2
    };

    void f();

    inline constexpr int k = 123;
}

consteval int countThingsInDemo()
{
    constexpr auto ctx = std::meta::access_context::current();

    auto ms = std::meta::members_of(^^demo, ctx);

    int types{};
    int funcs{};
    int vars{};

    for (std::meta::info m : ms)
    {
        if (is_type(m))
        {
            ++types;
        }

        if (is_function(m))
        {
            ++funcs;
        }

        if (is_variable(m))
        {
            ++vars;
        }
    }

    // S + E, f, k => 2 / 1 / 1 => overall 4
    return types + funcs + vars;
}

int main()
{
    std::println("Start 3:");

    constexpr int count = countThingsInDemo();

	static_assert(count == 4, "Expected 4 members in namespace 'demo'");

	std::println("Found {} members in namespace 'demo'.", count);

    std::println("Done.");
}

// =====================================================================================
// End-of-File
// =====================================================================================