Function TEST

library/cpp/iterator/ut/iterate_keys_ut.cpp:9–19

using namespace testing;

TEST(IterateKeys, ConstMappingIteration) {
    const std::map<int, int> squares{
        {1, 1},
        {2, 4},
        {3, 9},
    };
    EXPECT_THAT(
        IterateKeys(squares),
        ElementsAre(1, 2, 3)
    );
}

TEST(IterateKeys, ConstMultiMappingIteration) {
    const std::multimap<int, int> primesBelow{