kepka/Telegram/ThirdParty/variant/test/t/variant_alternative.cpp

32 lines
1.2 KiB
C++

#include "catch.hpp"
#include <mapbox/variant.hpp>
#include <mapbox/variant_io.hpp>
#include <string>
TEST_CASE("variant_alternative", "[types]")
{
using variant_type = mapbox::util::variant<int, double, std::string>;
using type_0 = mapbox::util::variant_alternative<0, variant_type>::type;
using type_1 = mapbox::util::variant_alternative<1, variant_type>::type;
using type_2 = mapbox::util::variant_alternative<2, variant_type>::type;
//using type_3 = mapbox::util::variant_alternative<3, variant_type>::type; // compile error
constexpr bool check_0 = std::is_same<int, type_0>::value;
constexpr bool check_1 = std::is_same<double, type_1>::value;
constexpr bool check_2 = std::is_same<std::string, type_2>::value;
CHECK(check_0);
CHECK(check_1);
CHECK(check_2);
}
TEST_CASE("variant_size", "[types]")
{
constexpr auto value_0 = mapbox::util::variant_size<mapbox::util::variant<>>::value;
constexpr auto value_1 = mapbox::util::variant_size<mapbox::util::variant<int>>::value;
constexpr auto value_2 = mapbox::util::variant_size<mapbox::util::variant<int, std::string>>::value;
CHECK(value_0 == 0);
CHECK(value_1 == 1);
CHECK(value_2 == 2);
}