ydb/util/generic/cast_ut.cpp

#include "cast.h"

#include <library/cpp/testing/unittest/registar.h>

class TGenericCastsTest: public TTestBase {
    UNIT_TEST_SUITE(TGenericCastsTest);
    UNIT_TEST(TestVerifyDynamicCast)
    UNIT_TEST(TestIntegralCast)
    UNIT_TEST(TestEnumCast)
    UNIT_TEST(TestToUnderlying)
    UNIT_TEST(TestBitCast)
    UNIT_TEST_SUITE_END();

private:
    struct TAaa {
        virtual ~TAaa() = default;
    };
    struct TBbb: public TAaa {};

    inline void TestVerifyDynamicCast() {
        TBbb bbb;
        TAaa* aaa = &bbb;
        TAaa* aaa2 = VerifyDynamicCast<TBbb*>(aaa);
        UNIT_ASSERT(aaa == aaa2);
    }

    void TestIntegralCast() {
        UNIT_ASSERT_EXCEPTION(SafeIntegerCast<ui32>(-5), TBadCastException);
        UNIT_ASSERT_EXCEPTION(SafeIntegerCast<ui16>(static_cast<i32>(Max<ui16>() + 10)), TBadCastException);
        UNIT_ASSERT_EXCEPTION(SafeIntegerCast<ui16>(static_cast<ui32>(Max<ui16>() + 10)), TBadCastException);
    }

    inline void TestEnumCast() {
        enum A {
            AM1 = -1
        };

        enum B: int {
            BM1 = -1
        };

        enum class C: unsigned short {
            CM1 = 1
        };

        UNIT_ASSERT_EXCEPTION(SafeIntegerCast<unsigned int>(AM1), TBadCastException);
        UNIT_ASSERT_EXCEPTION(SafeIntegerCast<unsigned int>(BM1), TBadCastException);
        UNIT_ASSERT_EXCEPTION(SafeIntegerCast<C>(AM1), TBadCastException);
        UNIT_ASSERT_EXCEPTION(static_cast<int>(SafeIntegerCast<C>(BM1)), TBadCastException);
        UNIT_ASSERT(SafeIntegerCast<A>(BM1) == AM1);
        UNIT_ASSERT(SafeIntegerCast<B>(AM1) == BM1);
        UNIT_ASSERT(SafeIntegerCast<A>(C::CM1) == 1);
        UNIT_ASSERT(SafeIntegerCast<B>(C::CM1) == 1);
        UNIT_ASSERT(SafeIntegerCast<A>(-1) == AM1);
        UNIT_ASSERT(SafeIntegerCast<B>(-1) == BM1);
        UNIT_ASSERT(SafeIntegerCast<C>(1) == C::CM1);
    }

    void TestToUnderlying() {
        enum A {
            AM1 = -1
        };

        enum B: int {
            BM1 = -1
        };

        enum class C: unsigned short {
            CM1 = 1
        };

        static_assert(static_cast<std::underlying_type_t<A>>(AM1) == ToUnderlying(AM1), "");
        static_assert(static_cast<std::underlying_type_t<B>>(BM1) == ToUnderlying(BM1), "");
        static_assert(static_cast<std::underlying_type_t<C>>(C::CM1) == ToUnderlying(C::CM1), "");

        static_assert(std::is_same<std::underlying_type_t<A>, decltype(ToUnderlying(AM1))>::value, "");
        static_assert(std::is_same<std::underlying_type_t<B>, decltype(ToUnderlying(BM1))>::value, "");
        static_assert(std::is_same<std::underlying_type_t<C>, decltype(ToUnderlying(C::CM1))>::value, "");

        UNIT_ASSERT_VALUES_EQUAL(static_cast<std::underlying_type_t<A>>(AM1), ToUnderlying(AM1));
        UNIT_ASSERT_VALUES_EQUAL(static_cast<std::underlying_type_t<B>>(BM1), ToUnderlying(BM1));
        UNIT_ASSERT_VALUES_EQUAL(static_cast<std::underlying_type_t<C>>(C::CM1), ToUnderlying(C::CM1));
    }

    void TestBitCast() {
        // Change sign of float
        {
            const float floatValue = 17.33f;
            ui32 ui32Value = BitCast<ui32>(floatValue);
            ui32Value ^= (ui32)1 << 31;
            UNIT_ASSERT_VALUES_EQUAL(-floatValue, BitCast<float>(ui32Value));
        }

        // Unpack ui64 into a struct
        {
            const ui64 value = 0x1122334455667788;
            struct TStruct {
                ui32 a;
                ui16 b;
                ui8 c;
                ui8 d;
            };
            auto structValue = BitCast<TStruct>(value);
            UNIT_ASSERT_VALUES_EQUAL(structValue.a, 0x55667788);
            UNIT_ASSERT_VALUES_EQUAL(structValue.b, 0x3344);
            UNIT_ASSERT_VALUES_EQUAL(structValue.c, 0x22);
            UNIT_ASSERT_VALUES_EQUAL(structValue.d, 0x11);
        }
    }
};

UNIT_TEST_SUITE_REGISTRATION(TGenericCastsTest);