control_constructs_common.hpp

C++的一个好库。。。现在很流行

// Boost Lambda Library -- control_constructs_common.hpp -------------------

// Copyright (C) 1999, 2000 Jaakko J鋜vi ([e-mail])
// Copyright (C) 2000 Gary Powell ([e-mail])
//
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//
// For more information, see www.boost.org

// --------------------------------------------------------------------------

#if !defined(BOOST_CONTROL_CONSTRUCTS_COMMON_HPP)
#define BOOST_CONTROL_CONSTRUCTS_COMMON_HPP

namespace boost { 
namespace lambda {

  // special types of lambda functors, used with control structures
  // to guarantee that they are composed correctly.

template<class Tag, class LambdaFunctor>
class tagged_lambda_functor;

template<class Tag, class Args>
class tagged_lambda_functor<Tag, lambda_functor<Args> > 
  : public lambda_functor<Args> 
{
public:
  tagged_lambda_functor(const Args& a) : lambda_functor<Args>(a) {}

  tagged_lambda_functor(const lambda_functor<Args>& a) 
    : lambda_functor<Args>(a) {}

  // for the no body cases in control structures.
  tagged_lambda_functor() : lambda_functor<Args>() {}
};

} // lambda
} // boost

#endif // BOOST_CONTROL_CONSTRUCTS_COMMON_HPP