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/utility/enable_if.hpp> 14 #include <boost/type_traits/is_arithmetic.hpp> 15 #include <boost/core/lightweight_test.hpp> 16 17 using boost::enable_if; 18 using boost::disable_if; 19 using boost::is_arithmetic; 20 21 template <int N> struct dummy { dummydummy22 dummy(int) {}; 23 }; 24 25 template<class T> 26 typename enable_if<is_arithmetic<T>, bool>::type arithmetic_object(T t,dummy<0>=0)27arithmetic_object(T t, dummy<0> = 0) { return true; } 28 29 template<class T> 30 typename disable_if<is_arithmetic<T>, bool>::type arithmetic_object(T t,dummy<1>=0)31arithmetic_object(T t, dummy<1> = 0) { return false; } 32 33 main()34int main() 35 { 36 37 BOOST_TEST(arithmetic_object(1)); 38 BOOST_TEST(arithmetic_object(1.0)); 39 40 BOOST_TEST(!arithmetic_object("1")); 41 BOOST_TEST(!arithmetic_object(static_cast<void*>(0))); 42 43 return boost::report_errors(); 44 } 45 46