KaixoCode / type_utils

Type utilities for things like template packs, structs, functions, enums. Complex template pack manipulation.

Type Utils

Type utilities library for things like template packs, structs, functions, enums.

using namespace kaixo;

struct Struct {
    int a;
    double b;
    float c;
};

int my_fun(double, long, int, float) { return 1; }

enum my_enum { Value1, Value2 };

// boolean operations on type traits
template<require<is_integral || is_floating_point> Ty> 
struct my_type {};

int main() {

    // Simple type traits
    static_assert(info<int>::is_integral); 
    static_assert(info<double[3][5]>::extent<1> == 5);
    static_assert(info<double, long, int, float>::can_invoke<decltype(my_fun)>);
    
    // Query function information
    static_assert(info_v<my_fun>::arguments::size == 4); 
    static_assert(same_as<info_v<my_fun>::result::type, int>); 
    static_assert(same_as<info_v<my_fun>::pointer::type, int(*)(double, long, int, float)>);

    // Query struct member types
    static_assert(info<Struct>::members::size == 3);
    static_assert(same_as<info<Struct>::members::element<0>::type, int>);

    // Complex template pack manipulation
    static_assert(info<int, double, float>::filter<is_integral>::size == 1);
    static_assert(info<int, double, int>::indices<int>.size() == 2); // result: std::array{ 0ull, 2ull }
    static_assert(same_as<info<int, double, int, float>::unique, info<int, double, float>>);
    static_assert(info<int, unsigned, float, double>::count_filter<is_integral> == 2);

    // Enum value names
    static_assert(info<my_enum>::name<Value1> == "Value1");
    static_assert(info<my_enum>::name<1> == "Value2");
    static_assert(info<my_enum>::defined<0> == true);
    static_assert(info<my_enum>::defined<3> == false);

    // Type manipulation
    static_assert(same_as<info<int&>::add_cvref_from<const int>::type, const int&>);
    static_assert(same_as<info<const int&>::copy_ref_to<int>::type, int&>);

    // Sort types
    static_assert(same_as<
        info<uint16_t, uint64_t, uint8_t, uint32_t>::sort<type_sorters::size_desc>,
        info<uint64_t, uint32_t, uint16_t, uint8_t>
    >);

    // Transform pack of types
    static_assert(same_as<
        info<std::vector<int>, std::vector<double>>::transform<grab::reference>,
        info<int&, double&>
    >);

    return 0;
}