CODEWITHSUNDEEP
c++visual-studio-2015overflow
Lisa
Lisa

Reputation: 4400

How to avoid Microsoft C26451 (arithmetic overflow) warning

How to code defensively against the Microsoft C26451 (arithmetic overflow) warning in my example? I feel like this should be trivial to fix. So frustrating!

    // Linear interpolation
    // target  - the target point, 0.0 - 1.0
    // x...    - two values {X1} {X2}
    inline static double Linear(float target, double x1, double x2) {
        return (target * x2) + ((1.0 - (double)target) * x1);
    }

I read through Arithmetic overflow: Using operator '*' on a 4 byte value then casting the result to a 8 byte value but can't seem to fix my C26451 warning: "Arithmetic overflow: Using operator '-' on a 4 byte value and then casting the result to a 8 byte value. Cast the value to the wider type before calling operator '-' to avoid overflow (io.2).

What would I do to remove the warning?

The Microsoft doc on their compile error did not really help. https://learn.microsoft.com/en-us/cpp/code-quality/c26451

Upvotes: 0

Views: 1011

Answers (1)

Ted Lyngmo
Ted Lyngmo

Reputation: 117298

The compiler warning doesn't make sense and newer Visual Studio versions does not give the same warning. I'd disable it for this line only:

inline static double Linear(double target, double x1, double x2) {
    #pragma warning( push )
    #pragma warning( disable : 26451 )
    return (target * x2) + ((1.0 - target) * x1);
    #pragma warning( pop )
}

Upvotes: 2

Related Questions