typelist-util.hpp

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/*
  TYPELIST-UTIL.hpp  -  simple helpers for working with lists-of-types

   Copyright (C)
     2008,            Hermann Vosseler <Ichthyostega@web.de>

  **Lumiera** is free software; you can redistribute it and/or modify it
  under the terms of the GNU General Public License as published by the
  Free Software Foundation; either version 2 of the License, or (at your
  option) any later version. See the file COPYING for further details.

*/


#ifndef LIB_META_TYPELIST_UTIL_H
#define LIB_META_TYPELIST_UTIL_H



#include "lib/meta/typelist.hpp"

namespace lib {
namespace meta {
    
    
    template<class TYPES>
    struct count;
    template<>
    struct count<NullType>
      {
        enum{ value = 0 };
      };
    template<class TY, class TYPES>
    struct count<Node<TY,TYPES>>
      {
        enum{ value = 1 + count<TYPES>::value };
      };
    
    
    template<class TYPES>
    struct maxSize;
    template<>
    struct maxSize<NullType>
      {
        static constexpr int value = 0;
      };
    template<class TY, class TYPES>
    struct maxSize<Node<TY,TYPES>>
      {
        static constexpr size_t thisval = sizeof(TY);
        static constexpr size_t nextval = maxSize<TYPES>::value;
        static constexpr size_t value   = nextval > thisval?  nextval:thisval;
      };
    
    
    template<class TYPES>
    struct maxAlign;
    template<>
    struct maxAlign<NullType>
      {
        static constexpr int value = 0;
      };
    template<class TY, class TYPES>
    struct maxAlign<Node<TY,TYPES>>
      {
        static constexpr size_t thisval = alignof(TY);
        static constexpr size_t nextval = maxAlign<TYPES>::value;
        static constexpr size_t value   = nextval > thisval?  nextval:thisval;
      };
    
    
    template<typename TY, typename TYPES>
    struct IsInList
      {
        enum{ value = false };
      };
    
    template<typename TY, typename TYPES>
    struct IsInList<TY, Node<TY,TYPES>>
      {
        enum{ value = true };
      };
    
    template<typename TY, typename XX, typename TYPES>
    struct IsInList<TY, Node<XX,TYPES>>
      {
        enum{ value = IsInList<TY,TYPES>::value };
      };
    
    template<typename TY, typename TYPES>
    constexpr bool
    isInList()
    {
      return IsInList<TY,TYPES>::value;
    }
    
    
    template<typename TYPES>
    struct ConstAll;
    
    template<>
    struct ConstAll<NullType>
      {
        typedef NullType List;
      };
    
    template<typename TY, typename TYPES>
    struct ConstAll<Node<TY,TYPES>>
      {
        typedef Node<const TY, typename ConstAll<TYPES>::List> List;
      };
    
    
    
}} // namespace lib::meta
#endif