| // 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 <boost/test/minimal.hpp> |
| |
| #include <boost/utility/enable_if.hpp> |
| #include <boost/type_traits.hpp> |
| |
| using boost::enable_if; |
| using boost::disable_if; |
| using boost::is_arithmetic; |
| |
| struct container { |
| bool my_value; |
| |
| template <class T> |
| container(const T&, const typename enable_if<is_arithmetic<T>, T>::type * = 0): |
| my_value(true) {} |
| |
| template <class T> |
| container(const T&, const typename disable_if<is_arithmetic<T>, T>::type * = 0): |
| my_value(false) {} |
| }; |
| |
| // example from Howard Hinnant (tests enable_if template members of a templated class) |
| template <class charT> |
| struct xstring |
| { |
| template <class It> |
| xstring(It begin, It end, typename |
| disable_if<is_arithmetic<It> >::type* = 0) |
| : data(end-begin) {} |
| |
| int data; |
| }; |
| |
| |
| int test_main(int, char*[]) |
| { |
| |
| BOOST_CHECK(container(1).my_value); |
| BOOST_CHECK(container(1.0).my_value); |
| |
| BOOST_CHECK(!container("1").my_value); |
| BOOST_CHECK(!container(static_cast<void*>(0)).my_value); |
| |
| char sa[] = "123456"; |
| BOOST_CHECK(xstring<char>(sa, sa+6).data == 6); |
| |
| |
| return 0; |
| } |
| |