1 
2 #ifndef BOOST_MPL_IDENTITY_HPP_INCLUDED
3 #define BOOST_MPL_IDENTITY_HPP_INCLUDED
4 
5 // Copyright Aleksey Gurtovoy 2000-2004
6 //
7 // Distributed under the Boost Software License, Version 1.0.
8 // (See accompanying file LICENSE_1_0.txt or copy at
9 // http://www.boost.org/LICENSE_1_0.txt)
10 //
11 // See http://www.boost.org/libs/mpl for documentation.
12 
13 // $Id$
14 // $Date$
15 // $Revision$
16 
17 #include <boost/mpl/aux_/na_spec.hpp>
18 #include <boost/mpl/aux_/lambda_support.hpp>
19 
20 namespace boost { namespace mpl {
21 
22 template<
23       typename BOOST_MPL_AUX_NA_PARAM(T)
24     >
25 struct identity
26 {
27     typedef T type;
28     BOOST_MPL_AUX_LAMBDA_SUPPORT(1, identity, (T))
29 };
30 
31 template<
32       typename BOOST_MPL_AUX_NA_PARAM(T)
33     >
34 struct make_identity
35 {
36     typedef identity<T> type;
37     BOOST_MPL_AUX_LAMBDA_SUPPORT(1, make_identity, (T))
38 };
39 
40 BOOST_MPL_AUX_NA_SPEC_NO_ETI(1, identity)
41 BOOST_MPL_AUX_NA_SPEC_NO_ETI(1, make_identity)
42 
43 }}
44 
45 #endif // BOOST_MPL_IDENTITY_HPP_INCLUDED
46