warning C4127: conditional expression is constant

[wbuck]

So this particular warning can become an issue when compiling with /WX and /W4. The following can trigger this warning:

SCENARIO("Minimum operation")
{
    const int x{ 2 };
    const int y{ 3 };
    REQUIRE(x < y);
}

I believe re-writing the REQUIRE macro to the following would correct the issue:

#define REQUIRE(expression) \
do { \
    ++assertions; \
    const auto result__ = (expression); \
    if (!result__) { \
        KMTEST_ASSERT(const_cast<char*>(#expression), const_cast<char*>(__FILE__), __LINE__, nullptr); \
        ++failures; \
    } \
} while (0)

It looks like the C4127 was being generated when evaluating the constant expression in the if statement of the original REQUIRE macro.

Maybe some more testing is needed in order to fully confirm this is the case for different compiler versions. Currently I've only tested this with VS2019 version 16.11.13 and VS2022 version 17.1.4.

[SergiusTheBest]

I think the warning is good in such case. It means that the expression and the assert result is evaluated during compile time. So you can use static_assert and have error detection during compile time instead of run time.

[SergiusTheBest]

The issue is fixed!

[SergiusTheBest]

Thank you!