Tiny C++ template metaprogramming helpers

template_metaprogramming_helpers.cpp

// https://vawale.github.io/posts/template_metaprogramming_helpers/

template<typename... Args>
consteval auto count() {
    return sizeof...(Args);
}

template<template <typename T> typename Predicate, typename... Args>
consteval auto count_if() -> size_t {
    return (0 + ... + Predicate<Args>{}());
}

template<typename T>
struct is_signed_type {
    consteval bool operator ()() const {
        return std::is_signed_v<T>;
    }
};

template<template <typename T> typename Predicate, typename... Args>
consteval auto all_of() -> bool {
    return (Predicate<Args>{}() && ...);
}

template<template <typename T> typename Predicate, typename... Args>
consteval auto any_of() -> bool {
    return (Predicate<Args>{}() || ...);
}

template<template <typename T> typename Predicate, typename... Args>
consteval auto none_of() -> bool {
    return !any_of<Predicate, Args...>();
}

template<template <typename T> typename Func, typename... Args>
consteval void for_each() {
    (Func<Args>{}(), ...);
}

template<typename T>
struct assert_arithmetic {
    consteval void operator ()() const {
        static_assert(std::is_arithmetic_v<T>, "T must be arithmetic type");
    }
};

template<template <typename T> typename Func, typename... Args>
consteval void for_each_tuple_type(std::tuple<Args...>) {
    (Func<Args>{}(), ...);
}

template<template <typename T> typename Func, template Tuple>
consteval void for_each_tuple_type() {
    auto evaluator = []<typename Tuple, template <typename T> typename Func, size_t... I>(std::index_sequence<I...>) {
        (Func<std::tuple_element_t<I, Tuple>>{}(), ...);
    };
    evaluator.template operator() <Tuple, Func>
    (std::make_index_sequence<std::tuple_size_v<Tuple>>());
}