// Boost enable_if library // 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) #include #include #include using boost::enable_if; using boost::disable_if; using boost::is_arithmetic; struct container { bool my_value; template container(const T&, const typename enable_if, T>::type * = 0): my_value(true) {} template container(const T&, const typename disable_if, T>::type * = 0): my_value(false) {} }; // example from Howard Hinnant (tests enable_if template members of a templated class) template struct xstring { template xstring(It begin, It end, typename disable_if >::type* = 0) : data(end-begin) {} int data; }; int main() { BOOST_TEST(container(1).my_value); BOOST_TEST(container(1.0).my_value); BOOST_TEST(!container("1").my_value); BOOST_TEST(!container(static_cast(0)).my_value); char sa[] = "123456"; BOOST_TEST(xstring(sa, sa+6).data == 6); return boost::report_errors(); }