dlib C++ Library - enable_if.h

// Copyright 2003 (C) The Trustees of Indiana University.
// Use, modification, and distribution is subject to 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)
// Authors: Jaakko Jarvi (jajarvi at osl.iu.edu)
// Jeremiah Willcock (jewillco at osl.iu.edu)
// Andrew Lumsdaine (lums at osl.iu.edu)
#ifndef DLIB_BOOST_UTILITY_ENABLE_IF_HPP
#define DLIB_BOOST_UTILITY_ENABLE_IF_HPP
namespace dlib 
{
 
 template <bool B, class T = void>
 struct enable_if_c {
 typedef T type;
 };
 template <class T>
 struct enable_if_c<false, T> {};
 template <class Cond, class T = void> 
 struct enable_if : public enable_if_c<Cond::value, T> {};
 template <bool B, class T>
 struct lazy_enable_if_c {
 typedef typename T::type type;
 };
 template <class T>
 struct lazy_enable_if_c<false, T> {};
 template <class Cond, class T> 
 struct lazy_enable_if : public lazy_enable_if_c<Cond::value, T> {};
 template <bool B, class T = void>
 struct disable_if_c {
 typedef T type;
 };
 template <class T>
 struct disable_if_c<true, T> {};
 template <class Cond, class T = void> 
 struct disable_if : public disable_if_c<Cond::value, T> {};
 template <bool B, class T>
 struct lazy_disable_if_c {
 typedef typename T::type type;
 };
 template <class T>
 struct lazy_disable_if_c<true, T> {};
 template <class Cond, class T> 
 struct lazy_disable_if : public lazy_disable_if_c<Cond::value, T> {};
} // namespace dlib 
#endif // DLIB_BOOST_UTILITY_ENABLE_IF_HPP