Filter.hpp

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//
//  CeresEngine - A game development framework
//
//  Created by Rogiel Sulzbach.
//  Copyright (c) 2018-2022 Rogiel Sulzbach. All rights reserved.
//
 
#pragma once
 
#include "Concat.hpp"
#include "TypeList.hpp"
 
#include <type_traits>
 
namespace CeresEngine::MPL {
 
    template<template<typename> class TTypePred, typename> struct FilterHelper { using type = TypeList<>; };
 
    template<template<typename> class TTypePred, typename TTypeList> using Filter = typename FilterHelper<TTypePred, TTypeList>::type;
 
    template<template<typename> class TTypePred, typename T, typename... Ts> struct FilterHelper<TTypePred, TypeList<T, Ts...>> {
        using Next = Filter<TTypePred, TypeList<Ts...>>;
        using type = std::conditional_t<TTypePred<T>::value, Concat<TypeList<T>, Next>, Next>;
    };
} // namespace CeresEngine::MPL