libs/fusion/test/sequence/construction.hpp

   1 /*=============================================================================
   2     Copyright (c) 1999-2003 Jaakko Jarvi
   3     Copyright (c) 2001-2011 Joel de Guzman
   4
   5     Distributed under the Boost Software License, Version 1.0. (See accompanying
   6     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   7 ==============================================================================*/
   8 #include <boost/detail/lightweight_test.hpp>
   9 #include <boost/fusion/sequence/intrinsic/at.hpp>
  10 #include <boost/fusion/container/list/cons.hpp>
  11
  12 #if !defined(FUSION_AT)
  13 #define FUSION_AT at_c
  14 #endif
  15
  16 namespace test_detail
  17 {
  18     // something to prevent warnings for unused variables
  19     template<class T> void dummy(const T&) {}
  20
  21     // no public default constructor
  22     class foo
  23     {
  24     public:
  25
  26         explicit foo(int v) : val(v) {}
  27
  28         bool operator==(const foo& other) const
  29         {
  30             return val == other.val;
  31         }
  32
  33     private:
  34
  35         foo() {}
  36         int val;
  37     };
  38
  39     // another class without a public default constructor
  40     class no_def_constructor
  41     {
  42         no_def_constructor() {}
  43
  44     public:
  45
  46         no_def_constructor(std::string) {}
  47     };
  48 }
  49
  50 inline void
  51 test()
  52 {
  53     using namespace boost::fusion;
  54     using namespace test_detail;
  55
  56     nil empty;
  57
  58     FUSION_SEQUENCE<> empty0;
  59
  60 #ifndef NO_CONSTRUCT_FROM_NIL
  61     FUSION_SEQUENCE<> empty1(empty);
  62 #endif
  63
  64     FUSION_SEQUENCE<int> t1;
  65     BOOST_TEST(FUSION_AT<0>(t1) == int());
  66
  67     FUSION_SEQUENCE<float> t2(5.5f);
  68     BOOST_TEST(FUSION_AT<0>(t2) > 5.4f && FUSION_AT<0>(t2) < 5.6f);
  69
  70     FUSION_SEQUENCE<foo> t3(foo(12));
  71     BOOST_TEST(FUSION_AT<0>(t3) == foo(12));
  72
  73     FUSION_SEQUENCE<double> t4(t2);
  74     BOOST_TEST(FUSION_AT<0>(t4) > 5.4 && FUSION_AT<0>(t4) < 5.6);
  75
  76     FUSION_SEQUENCE<int, float> t5;
  77     BOOST_TEST(FUSION_AT<0>(t5) == int());
  78     BOOST_TEST(FUSION_AT<1>(t5) == float());
  79
  80     FUSION_SEQUENCE<int, float> t6(12, 5.5f);
  81     BOOST_TEST(FUSION_AT<0>(t6) == 12);
  82     BOOST_TEST(FUSION_AT<1>(t6) > 5.4f && FUSION_AT<1>(t6) < 5.6f);
  83
  84     FUSION_SEQUENCE<int, float> t7(t6);
  85     BOOST_TEST(FUSION_AT<0>(t7) == 12);
  86     BOOST_TEST(FUSION_AT<1>(t7) > 5.4f && FUSION_AT<1>(t7) < 5.6f);
  87
  88     FUSION_SEQUENCE<long, double> t8(t6);
  89     BOOST_TEST(FUSION_AT<0>(t8) == 12);
  90     BOOST_TEST(FUSION_AT<1>(t8) > 5.4f && FUSION_AT<1>(t8) < 5.6f);
  91
  92     dummy
  93     (
  94         FUSION_SEQUENCE<no_def_constructor, no_def_constructor, no_def_constructor>(
  95             std::string("Jaba"),        // ok, since the default
  96             std::string("Daba"),        // constructor is not used
  97             std::string("Doo")
  98         )
  99     );
 100
 101     dummy(FUSION_SEQUENCE<int, double>());
 102     dummy(FUSION_SEQUENCE<int, double>(1,3.14));
 103
 104 #if defined(FUSION_TEST_FAIL)
 105     dummy(FUSION_SEQUENCE<double&>());          // should fail, no defaults for references
 106     dummy(FUSION_SEQUENCE<const double&>());    // likewise
 107 #endif
 108
 109     {
 110         double dd = 5;
 111         dummy(FUSION_SEQUENCE<double&>(dd)); // ok
 112         dummy(FUSION_SEQUENCE<const double&>(dd+3.14)); // ok, but dangerous
 113     }
 114
 115 #if defined(FUSION_TEST_FAIL)
 116     dummy(FUSION_SEQUENCE<double&>(dd+3.14));   // should fail,
 117                                                 // temporary to non-const reference
 118 #endif
 119 }