replace

#pragma once

#include "typelist.h"

template<typename TList, typename OldType, typename NewType>
struct Replace;

template<typename OldType, typename NewType>
struct Replace<NullType,OldType,NewType>{
    typedef NullType NewTypeList;
};

template<typename Tail, typename OldType, typename NewType>
struct Replace<TypeList<OldType, Tail>, OldType, NewType>{
    typedef TypeList<NewType,Tail> NewTypeList;
};

template <typename Head, typename Tail, typename OldType, typename NewType>
struct Replace<TypeList<Head,Tail>, OldType, NewType>{
    typedef TypeList<Head,
        typename Replace<Tail,OldType,NewType>::NewTypeList> NewTypeList;
};