81 lines
2.2 KiB
C++
81 lines
2.2 KiB
C++
///////////////////////////////////////////////////////////////////////////////
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// cpp-next_bug.hpp
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//
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// Copyright 2012 Eric Niebler. Distributed under the Boost
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// Software License, Version 1.0. (See accompanying file
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// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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#include <vector>
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#include <boost/proto/proto.hpp>
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#include <boost/test/unit_test.hpp>
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namespace mpl = boost::mpl;
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namespace proto = boost::proto;
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using proto::_;
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namespace linear_algebra
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{
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// A trait that returns true only for std::vector
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template<typename T>
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struct is_std_vector
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: mpl::false_
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{};
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template<typename T, typename A>
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struct is_std_vector<std::vector<T, A> >
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: mpl::true_
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{};
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// A type used as a domain for linear algebra expressions
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struct linear_algebra_domain
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: proto::domain<>
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{};
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// Define all the operator overloads for combining std::vectors
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BOOST_PROTO_DEFINE_OPERATORS(is_std_vector, linear_algebra_domain)
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// Take any expression and turn each node
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// into a subscript expression, using the
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// state as the RHS.
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struct Distribute
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: proto::or_<
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proto::when<proto::terminal<_>, proto::_make_subscript(_, proto::_state)>
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, proto::plus<Distribute, Distribute>
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>
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{};
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struct Optimize
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: proto::or_<
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proto::when<
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proto::subscript<Distribute, proto::terminal<_> >,
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Distribute(proto::_left, proto::_right)
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>
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, proto::plus<Optimize, Optimize>
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, proto::terminal<_>
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>
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{};
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}
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static const int celems = 4;
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static int const value[celems] = {1,2,3,4};
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std::vector<int> A(value, value+celems), B(A);
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void test1()
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{
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using namespace linear_algebra;
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proto::_default<> eval;
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BOOST_CHECK_EQUAL(8, eval(Optimize()((A + B)[3])));
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}
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using namespace boost::unit_test;
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///////////////////////////////////////////////////////////////////////////////
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// init_unit_test_suite
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//
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test_suite* init_unit_test_suite( int argc, char* argv[] )
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{
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test_suite *test = BOOST_TEST_SUITE("test for a problem reported on the cpp-next.com blog");
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test->add(BOOST_TEST_CASE(&test1));
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return test;
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}
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