osrm-backend/third_party/variant/test/t/sizeof.cpp

53 lines
1.7 KiB
C++

#include <algorithm>
#include <cstddef>
#include <cstdint>
#include "catch.hpp"
#include "variant.hpp"
#include "variant_io.hpp"
struct some_struct
{
int a;
bool b;
std::string c;
};
using variant_internal_index_type = size_t;
TEST_CASE("size of variants")
{
constexpr const auto min_overhead = sizeof(variant_internal_index_type);
using namespace std; // workaround for bug in GCC <= 4.8 where max_align_t is not in std
constexpr const auto max_overhead = alignof(max_align_t) + min_overhead;
using v1 = mapbox::util::variant<int>;
using v2 = mapbox::util::variant<int, bool, int64_t>;
using v3 = mapbox::util::variant<int, std::string>;
using v4 = mapbox::util::variant<std::string, std::string>;
using v5 = mapbox::util::variant<some_struct>;
constexpr const auto si = sizeof(int);
constexpr const auto sb = sizeof(bool);
constexpr const auto si64 = sizeof(int64_t);
constexpr const auto sd = sizeof(double);
constexpr const auto sstr = sizeof(std::string);
constexpr const auto spi = sizeof(std::pair<int, int>);
constexpr const auto ss = sizeof(some_struct);
REQUIRE(sizeof(v1) <= max_overhead + si);
REQUIRE(sizeof(v2) <= max_overhead + std::max({si, sb, si64}));
REQUIRE(sizeof(v3) <= max_overhead + std::max({si, sstr}));
REQUIRE(sizeof(v4) <= max_overhead + sstr);
REQUIRE(sizeof(v5) <= max_overhead + ss);
REQUIRE(sizeof(v1) >= min_overhead + si);
REQUIRE(sizeof(v2) >= min_overhead + std::max({si, sb, si64}));
REQUIRE(sizeof(v3) >= min_overhead + std::max({si, sstr}));
REQUIRE(sizeof(v4) >= min_overhead + sstr);
REQUIRE(sizeof(v5) >= min_overhead + ss);
}