variant_default_construct_cx.cpp 1.0 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051
  1. // Copyright 2017 Peter Dimov.
  2. //
  3. // Distributed under the Boost Software License, Version 1.0.
  4. //
  5. // See accompanying file LICENSE_1_0.txt or copy at
  6. // http://www.boost.org/LICENSE_1_0.txt
  7. #include <boost/variant2/variant.hpp>
  8. using namespace boost::variant2;
  9. #define STATIC_ASSERT(...) static_assert(__VA_ARGS__, #__VA_ARGS__)
  10. int main()
  11. {
  12. {
  13. constexpr variant<int> v;
  14. STATIC_ASSERT( v.index() == 0 );
  15. STATIC_ASSERT( get<0>(v) == 0 );
  16. }
  17. {
  18. constexpr variant<int const> v;
  19. STATIC_ASSERT( v.index() == 0 );
  20. STATIC_ASSERT( get<0>(v) == 0 );
  21. }
  22. {
  23. constexpr variant<int, float> v;
  24. STATIC_ASSERT( v.index() == 0 );
  25. STATIC_ASSERT( get<0>(v) == 0 );
  26. }
  27. {
  28. constexpr variant<int, int, float> v;
  29. STATIC_ASSERT( v.index() == 0 );
  30. STATIC_ASSERT( get<0>(v) == 0 );
  31. }
  32. {
  33. constexpr variant<int, float, float> v;
  34. STATIC_ASSERT( v.index() == 0 );
  35. STATIC_ASSERT( get<0>(v) == 0 );
  36. }
  37. }