callable_traits/test/remove_args_function_ptr.cpp

#include <tuple>
#include <utility>
#include <type_traits>
#include <callable_traits/callable_traits.hpp>

#ifndef CT_ASSERT
#define CT_ASSERT(...) static_assert(__VA_ARGS__, #__VA_ARGS__)
#endif //CT_ASSERT

namespace ct = callable_traits;

template<int I>
struct N {};

template<typename... Ts>
using sig = int(*)(Ts...);

int main() {

    {
        using f = sig<N<0>, N<1>, N<2>, N<3>, N<4>>;
        using test = ct::remove_args_t<0, f>;
        using expect = sig<N<1>, N<2>, N<3>, N<4>>;
        CT_ASSERT(std::is_same<test, expect>::value);
    }

    {
        using f = sig<N<0>, N<1>, N<2>, N<3>, N<4>>;
        using test = ct::remove_args_t<1, f>;
        using expect = sig<N<0>, N<2>, N<3>, N<4>>;
        CT_ASSERT(std::is_same<test, expect>::value);
    }

    {
        using f = sig<N<0>, N<1>, N<2>, N<3>, N<4>>;
        using test = ct::remove_args_t<2, f>;
        using expect = sig<N<0>, N<1>, N<3>, N<4>>;
        CT_ASSERT(std::is_same<test, expect>::value);
    }

    {
        using f = sig<N<0>, N<1>, N<2>, N<3>, N<4>>;
        using test = ct::remove_args_t<3, f>;
        using expect = sig<N<0>, N<1>, N<2>, N<4>>;
        CT_ASSERT(std::is_same<test, expect>::value);
    }

    {
        using f = sig<N<0>, N<1>, N<2>, N<3>, N<4>>;
        using test = ct::remove_args_t<4, f>;
        using expect = sig<N<0>, N<1>, N<2>, N<3>>;
        CT_ASSERT(std::is_same<test, expect>::value);
    }

    {
        using f = sig<N<0>, N<1>, N<2>, N<3>, N<4>>;
        using test = ct::remove_args_t<0, f, 5>;
        using expect = sig<>;
        CT_ASSERT(std::is_same<test, expect>::value);
    }

    {
        using f = sig<N<0>, N<1>, N<2>, N<3>, N<4>>;
        using test = ct::remove_args_t<0, f, 3>;
        using expect = sig<N<3>, N<4>>;
        CT_ASSERT(std::is_same<test, expect>::value);
    }

    {
        using f = sig<N<0>, N<1>, N<2>, N<3>, N<4>>;
        using test = ct::remove_args_t<3, f, 2>;
        using expect = sig<N<0>, N<1>, N<2>>;
        CT_ASSERT(std::is_same<test, expect>::value);
    }

    {
        using f = sig<N<0>, N<1>, N<2>, N<3>, N<4>>;
        using test = ct::remove_args_t<4, f, 1>;
        using expect = sig<N<0>, N<1>, N<2>, N<3>>;
        CT_ASSERT(std::is_same<test, expect>::value);
    }
}