libcxx

libcxx mirror with random patches
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index.pass.cpp (1350B)


      1 // -*- C++ -*-
      2 //===----------------------------------------------------------------------===//
      3 //
      4 //                     The LLVM Compiler Infrastructure
      5 //
      6 // This file is dual licensed under the MIT and the University of Illinois Open
      7 // Source Licenses. See LICENSE.TXT for details.
      8 //
      9 //===----------------------------------------------------------------------===//
     10 
     11 // UNSUPPORTED: c++98, c++03, c++11, c++14
     12 
     13 // <variant>
     14 
     15 // template <class ...Types> class variant;
     16 
     17 // constexpr size_t index() const noexcept;
     18 
     19 #include <cassert>
     20 #include <string>
     21 #include <type_traits>
     22 #include <variant>
     23 
     24 #include "archetypes.hpp"
     25 #include "test_macros.h"
     26 #include "variant_test_helpers.hpp"
     27 
     28 
     29 int main() {
     30   {
     31     using V = std::variant<int, long>;
     32     constexpr V v;
     33     static_assert(v.index() == 0, "");
     34   }
     35   {
     36     using V = std::variant<int, long>;
     37     V v;
     38     assert(v.index() == 0);
     39   }
     40   {
     41     using V = std::variant<int, long>;
     42     constexpr V v(std::in_place_index<1>);
     43     static_assert(v.index() == 1, "");
     44   }
     45   {
     46     using V = std::variant<int, std::string>;
     47     V v("abc");
     48     assert(v.index() == 1);
     49     v = 42;
     50     assert(v.index() == 0);
     51   }
     52 #ifndef TEST_HAS_NO_EXCEPTIONS
     53   {
     54     using V = std::variant<int, MakeEmptyT>;
     55     V v;
     56     assert(v.index() == 0);
     57     makeEmpty(v);
     58     assert(v.index() == std::variant_npos);
     59   }
     60 #endif
     61 }