libs/contract/test/call_if/equal_to.cpp

   1
   2 // Copyright (C) 2008-2018 Lorenzo Caminiti
   3 // Distributed under the Boost Software License, Version 1.0 (see accompanying
   4 // file LICENSE_1_0.txt or a copy at http://www.boost.org/LICENSE_1_0.txt).
   5 // See: http://www.boost.org/doc/libs/release/libs/contract/doc/html/index.html
   6
   7 // Test STL equal_to with call_if.
   8
   9 // C++17 warning from Boost.Bind.
  10 #define _SILENCE_CXX17_ADAPTOR_TYPEDEFS_DEPRECATION_WARNING
  11
  12 #include "../detail/oteststream.hpp"
  13 #include <boost/contract/call_if.hpp>
  14 #include <boost/bind.hpp>
  15 #include <boost/type_traits/has_equal_to.hpp>
  16 #include <boost/detail/lightweight_test.hpp>
  17 #include <functional>
  18 #include <sstream>
  19 #include <ios>
  20
  21 boost::contract::test::detail::oteststream out;
  22
  23 template<typename T>
  24 struct void_equal_to {
  25     typedef void result_type; // Test void result type.
  26
  27     void operator()(T const& left, T const& right) const {
  28         out << (left == right) << std::endl;
  29     }
  30 };
  31
  32 struct x {}; // Doest not have operator==.
  33
  34 int main() {
  35     std::ostringstream ok;
  36     ok << std::boolalpha;
  37     out << std::boolalpha;
  38     x x1, x2;;
  39
  40     out.str("");
  41     out << // Test on true condition with non-void result type.
  42         boost::contract::call_if<boost::has_equal_to<int> >(
  43             boost::bind(std::equal_to<int>(), 123, 123) // True.
  44         ).else_(
  45             // Compiler-error... but not called.
  46             boost::bind(std::equal_to<x>(), x1, x2)
  47         )
  48     << std::endl;
  49     ok.str(""); ok << true << std::endl;
  50     BOOST_TEST(out.eq(ok.str()));
  51
  52     out.str("");
  53     out << // Test on false condition with non-void result type.
  54         boost::contract::call_if<boost::has_equal_to<x> >(
  55             // Compiler-error... but not called.
  56             boost::bind(std::equal_to<x>(), x1, x2)
  57         ).else_([] { return true; })
  58     << std::endl;
  59     ok.str(""); ok << true << std::endl;
  60     BOOST_TEST(out.eq(ok.str()));
  61
  62     out.str("");
  63     // Test on true condition void result type.
  64     boost::contract::call_if<boost::has_equal_to<int> >(
  65         boost::bind(void_equal_to<int>(), 123, 456) // False.
  66     ).else_(
  67         // Compiler-error... but not called.
  68         boost::bind(void_equal_to<x>(), x1, x1)
  69     );
  70     ok.str(""); ok << false << std::endl;
  71     BOOST_TEST(out.eq(ok.str()));
  72
  73     out.str("");
  74     // Test on false condition with void result type.
  75     boost::contract::call_if<boost::has_equal_to<x> >(
  76         // Compiler-error... but not called.
  77         boost::bind(void_equal_to<x>(), x1, x1)
  78     ).else_(
  79         boost::bind(void_equal_to<int>(), 123, 456) // False.
  80     );
  81     ok.str(""); ok << false << std::endl;
  82     BOOST_TEST(out.eq(ok.str()));
  83
  84     return boost::report_errors();
  85 }
  86