ceph/src/boost/libs/proto/test/cpp-next_bug.cpp

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // cpp-next_bug.hpp
   3 //
   4 //  Copyright 2012 Eric Niebler. Distributed under the Boost
   5 //  Software License, Version 1.0. (See accompanying file
   6 //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   7
   8 #include <vector>
   9 #include <boost/proto/proto.hpp>
  10 #include <boost/test/unit_test.hpp>
  11 namespace mpl = boost::mpl;
  12 namespace proto = boost::proto;
  13 using proto::_;
  14
  15 namespace linear_algebra
  16 {
  17     // A trait that returns true only for std::vector
  18     template<typename T>
  19     struct is_std_vector
  20       : mpl::false_
  21     {};
  22
  23     template<typename T, typename A>
  24     struct is_std_vector<std::vector<T, A> >
  25       : mpl::true_
  26     {};
  27
  28     // A type used as a domain for linear algebra expressions
  29     struct linear_algebra_domain
  30       : proto::domain<>
  31     {};
  32
  33     // Define all the operator overloads for combining std::vectors
  34     BOOST_PROTO_DEFINE_OPERATORS(is_std_vector, linear_algebra_domain)
  35
  36     // Take any expression and turn each node
  37     // into a subscript expression, using the
  38     // state as the RHS.
  39     struct Distribute
  40       : proto::or_<
  41             proto::when<proto::terminal<_>, proto::_make_subscript(_, proto::_state)>
  42           , proto::plus<Distribute, Distribute>
  43         >
  44     {};
  45
  46     struct Optimize
  47       : proto::or_<
  48             proto::when<
  49                 proto::subscript<Distribute, proto::terminal<_> >,
  50                 Distribute(proto::_left, proto::_right)
  51             >
  52           , proto::plus<Optimize, Optimize>
  53           , proto::terminal<_>
  54         >
  55     {};
  56 }
  57
  58 static const int celems = 4;
  59 static int const value[celems] = {1,2,3,4};
  60 std::vector<int> A(value, value+celems), B(A);
  61
  62 void test1()
  63 {
  64     using namespace linear_algebra;
  65     proto::_default<> eval;
  66     BOOST_CHECK_EQUAL(8, eval(Optimize()((A + B)[3])));
  67 }
  68
  69 using namespace boost::unit_test;
  70 ///////////////////////////////////////////////////////////////////////////////
  71 // init_unit_test_suite
  72 //
  73 test_suite* init_unit_test_suite( int argc, char* argv[] )
  74 {
  75     test_suite *test = BOOST_TEST_SUITE("test for a problem reported on the cpp-next.com blog");
  76
  77     test->add(BOOST_TEST_CASE(&test1));
  78
  79     return test;
  80 }