PartialR.md

<CppML/Functional/PartialR.hpp>

PartialR

template <typename F, typename ...Args>
struct PartialR {
  template <typename ...Ts>
  using f = /* .... */;
};

PartialR<F, Args...>

PartialR<F, Args...> is a metafunction, that is a partial evaluation of F. When invoked on Ts..., it is as if F was invoked on Ts..., Args....

f:: Ts... -> F(Ts..., Args...)

Example

We can create a metafunction that checks if alignment of a type T is greater than alignment int, by taking ml::Map of ml::AlignOf that has ml::Greater as Pipe, and partially evaluate it on the right by int.

using IsMoreThanInt = 
          ml::PartialR<
              ml::Map<
                ml::AlignOf<>,
                ml::Greater<>>,
              int>;

using T0 = ml::f<F, float>;
using T1 = ml::f<F, double>;
static_assert(
        std::is_same_v<
                T0, ml::Bool<false>>);
static_assert(
        std::is_same_v<
                T1, ml::Bool<true>>);