1 // Boost enable_if library
2 
3 // Copyright 2003 (c) The Trustees of Indiana University.
4 
5 // Use, modification, and distribution is subject to the Boost Software
6 // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
7 // http://www.boost.org/LICENSE_1_0.txt)
8 
9 //    Authors: Jaakko Jarvi (jajarvi at osl.iu.edu)
10 //             Jeremiah Willcock (jewillco at osl.iu.edu)
11 //             Andrew Lumsdaine (lums at osl.iu.edu)
12 
13 #include <boost/config.hpp>
14 #include <boost/utility/enable_if.hpp>
15 #include <boost/type_traits/is_arithmetic.hpp>
16 #include <boost/core/lightweight_test.hpp>
17 
18 using boost::enable_if;
19 using boost::is_arithmetic;
20 
21 template<class T> struct not_
22 {
23   BOOST_STATIC_CONSTANT( bool, value = !T::value );
24 };
25 
26 namespace A {
27   template<class T>
28   typename enable_if<is_arithmetic<T>, bool>::type
arithmetic_object(T t)29   arithmetic_object(T t) { return true; }
30 }
31 
32 namespace B {
33   template<class T>
34   typename enable_if<not_<is_arithmetic<T> >, bool>::type
arithmetic_object(T t)35   arithmetic_object(T t) { return false; }
36 }
37 
main()38 int main()
39 {
40   using namespace A;
41   using namespace B;
42   BOOST_TEST(arithmetic_object(1));
43   BOOST_TEST(arithmetic_object(1.0));
44 
45   BOOST_TEST(!arithmetic_object("1"));
46   BOOST_TEST(!arithmetic_object(static_cast<void*>(0)));
47 
48   return boost::report_errors();
49 }
50 
51