forked from boostorg/core
99 lines
2.1 KiB
C++
99 lines
2.1 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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// Testing all variations of lazy_enable_if.
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#include <boost/utility/enable_if.hpp>
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#include <boost/type_traits/is_same.hpp>
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#include <boost/detail/lightweight_test.hpp>
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using boost::lazy_enable_if;
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using boost::lazy_disable_if;
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using boost::lazy_enable_if_c;
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using boost::lazy_disable_if_c;
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template <class T>
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struct is_int_or_double {
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BOOST_STATIC_CONSTANT(bool,
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value = (boost::is_same<T, int>::value ||
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boost::is_same<T, double>::value));
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};
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template <class T>
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struct some_traits {
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typedef typename T::does_not_exist type;
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};
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template <>
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struct some_traits<int> {
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typedef bool type;
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};
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template <>
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struct some_traits<double> {
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typedef bool type;
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};
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template <class T>
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struct make_bool {
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typedef bool type;
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};
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template <>
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struct make_bool<int> {};
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template <>
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struct make_bool<double> {};
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namespace A {
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template<class T>
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typename lazy_enable_if<is_int_or_double<T>, some_traits<T> >::type
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foo(T t) { return true; }
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template<class T>
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typename lazy_enable_if_c<is_int_or_double<T>::value, some_traits<T> >::type
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foo2(T t) { return true; }
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}
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namespace B {
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template<class T>
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typename lazy_disable_if<is_int_or_double<T>, make_bool<T> >::type
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foo(T t) { return false; }
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template<class T>
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typename lazy_disable_if_c<is_int_or_double<T>::value, make_bool<T> >::type
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foo2(T t) { return false; }
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}
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int main()
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{
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using namespace A;
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using namespace B;
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BOOST_TEST(foo(1));
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BOOST_TEST(foo(1.0));
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BOOST_TEST(!foo("1"));
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BOOST_TEST(!foo(static_cast<void*>(0)));
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BOOST_TEST(foo2(1));
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BOOST_TEST(foo2(1.0));
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BOOST_TEST(!foo2("1"));
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BOOST_TEST(!foo2(static_cast<void*>(0)));
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return boost::report_errors();
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}
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