62 lines
1.5 KiB
C++
62 lines
1.5 KiB
C++
// Boost enable_if library
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// Copyright 2003 (c) The Trustees of Indiana University.
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// Use, modification, and distribution is subject to the Boost Software
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// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt)
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// Authors: Jaakko Jarvi (jajarvi at osl.iu.edu)
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// Jeremiah Willcock (jewillco at osl.iu.edu)
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// Andrew Lumsdaine (lums at osl.iu.edu)
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#include <boost/utility/enable_if.hpp>
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#include <boost/type_traits.hpp>
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#include <boost/core/lightweight_test.hpp>
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using boost::enable_if;
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using boost::disable_if;
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using boost::is_arithmetic;
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struct container {
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bool my_value;
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template <class T>
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container(const T&, const typename enable_if<is_arithmetic<T>, T>::type * = 0):
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my_value(true) {}
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template <class T>
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container(const T&, const typename disable_if<is_arithmetic<T>, T>::type * = 0):
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my_value(false) {}
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};
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// example from Howard Hinnant (tests enable_if template members of a templated class)
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template <class charT>
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struct xstring
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{
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template <class It>
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xstring(It begin, It end, typename
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disable_if<is_arithmetic<It> >::type* = 0)
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: data(end-begin) {}
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int data;
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};
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int main()
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{
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BOOST_TEST(container(1).my_value);
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BOOST_TEST(container(1.0).my_value);
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BOOST_TEST(!container("1").my_value);
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BOOST_TEST(!container(static_cast<void*>(0)).my_value);
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char sa[] = "123456";
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BOOST_TEST(xstring<char>(sa, sa+6).data == 6);
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return boost::report_errors();
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}
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