diff options
| -rw-r--r-- | libs/kstd/kstd/bitfield_enum.tests.cpp | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/libs/kstd/kstd/bitfield_enum.tests.cpp b/libs/kstd/kstd/bitfield_enum.tests.cpp new file mode 100644 index 00000000..e0673269 --- /dev/null +++ b/libs/kstd/kstd/bitfield_enum.tests.cpp @@ -0,0 +1,159 @@ +#include <kstd/bitfield_enum.hpp> + +#include <catch2/catch_test_macros.hpp> + +#include <cstdint> +#include <type_traits> +#include <utility> + +namespace +{ + + enum struct test_enum : std::uint8_t + { + none = 0, + flag_a = 1, + flag_b = 2, + // INTENTIONAL HOLE + flag_c = 8, + flag_d = 16 + }; + +} // namespace + +template<> +struct kstd::is_bitfield_enum<test_enum> : std::true_type +{ +}; + +SCENARIO("Bitfield Enum operations") +{ + GIVEN("Two enumerator values") + { + auto value_one = test_enum::flag_a; + auto value_two = test_enum::flag_b; + + WHEN("combining them using bitwise or") + { + auto result = value_one | value_two; + + THEN("the underlying value is the bitwise combination of the two underlying values") + { + REQUIRE(std::to_underlying(result) == + (std::to_underlying(test_enum::flag_a) | std::to_underlying(test_enum::flag_b))); + } + } + + WHEN("combining them using bitwise or-assign") + { + auto result = value_one; + result |= value_two; + + THEN("the assigned to value is the bitwise combination of hte two values") + { + REQUIRE(result == (value_one | value_two)); + } + } + + WHEN("masking a combination using bitwise and and a present flag") + { + auto combination = test_enum::flag_a | test_enum::flag_b | test_enum::flag_c; + auto result = combination & test_enum::flag_b; + + THEN("the single flag is extracted") + { + REQUIRE(result == test_enum::flag_b); + } + } + + WHEN("masking a combination using bitwise and and a non-present flag") + { + auto combination = test_enum::flag_a | test_enum::flag_b | test_enum::flag_c; + auto result = combination & test_enum::flag_d; + + THEN("the single flag is extracted") + { + REQUIRE(result == test_enum::none); + } + } + + WHEN("masking a combination using bitwise and-assign and a present flag") + { + auto combination = test_enum::flag_a | test_enum::flag_b | test_enum::flag_c; + combination &= test_enum::flag_b; + + THEN("the single flag is extracted") + { + REQUIRE(combination == test_enum::flag_b); + } + } + + WHEN("masking a combination using bitwise and-assign and a non-present flag") + { + auto combination = test_enum::flag_a | test_enum::flag_b | test_enum::flag_c; + combination &= test_enum::flag_d; + + THEN("the single flag is extracted") + { + REQUIRE(combination == test_enum::none); + } + } + + WHEN("toggling a flag in a combination using bitwise xor") + { + auto combination = test_enum::flag_a | test_enum::flag_b; + auto result_absent = combination ^ test_enum::flag_c; + auto result_present = combination ^ test_enum::flag_b; + + THEN("the flag is set if it wasn't before") + { + CHECK((combination & test_enum::flag_c) == test_enum::none); + REQUIRE((result_absent & test_enum::flag_c) == test_enum::flag_c); + } + + THEN("the flag is not set if it was before") + { + CHECK((combination & test_enum::flag_b) == test_enum::flag_b); + REQUIRE_FALSE((result_present & test_enum::flag_b) == test_enum::flag_b); + } + } + + WHEN("toggling a flag in a combination using bitwise xor-assign") + { + auto combination = test_enum::flag_a | test_enum::flag_b; + auto result = combination; + result ^= test_enum::flag_c; + result ^= test_enum::flag_b; + + THEN("the flag is set if it wasn't before") + { + CHECK((combination & test_enum::flag_c) == test_enum::none); + REQUIRE((result & test_enum::flag_c) == test_enum::flag_c); + } + + THEN("the flag is not set if it was before") + { + CHECK((combination & test_enum::flag_b) == test_enum::flag_b); + REQUIRE_FALSE((result & test_enum::flag_b) == test_enum::flag_b); + } + } + + WHEN("inverting a combination using bitwise negation") + { + auto combination = test_enum::flag_a | test_enum::flag_c; + auto result = ~combination; + + THEN("all previously set flags are unset") + { + REQUIRE_FALSE((result & test_enum::flag_a) == test_enum::flag_a); + REQUIRE_FALSE((result & test_enum::flag_c) == test_enum::flag_c); + } + + THEN("all previously unset flags are set") + { + REQUIRE((result & test_enum::flag_b) == test_enum::flag_b); + REQUIRE((result & test_enum::flag_d) == test_enum::flag_d); + } + } + } +} |