# V1065. Expression can be simplified: check similar operands.

The analyzer has detected a suspicious expression that can be simplified by removing identical operands. Such expressions may indicate the presence of a logic error or typo.

Consider a simple contrived example:

    void Foo(int A, int B, int C)
    {
      if (A - A + 1 < C)
        Go(A, B);
    }

A typo makes this expression redundant and, therefore, reducible to '1 < C'. But in reality, the expression was meant to look, for example, like this:

    void Foo(int A, int B, int C)
    {
      if (A - B + 1 < C)
        Go(A, B);
    }

In other cases, such redundant expressions are technically correct, but the code will still benefit from simplifying them as it will help make them more concise. For example:

    if ((rec.winDim.left + (rec.winDim.right - rec.winDim.left)) < inset) // <=
    {
      rec.winDim.left  = -((rec.winDim.right – rec.winDim.left) - inset);
      rec.winDim.right = inset;
    }

    if ((rec.winDim.top + (rec.winDim.bottom – rec.winDim.top)) < inset) // <=
    {
      rec.winDim.top = -((rec.winDim.bottom – rec.winDim.top) - inset);
      rec.winDim.bottom = inset;
    }

In both conditions, the expressions can be simplified by removing, respectively, the operands 'rec.winDim.left' and 'rec.winDim.top'. Simplified version:

    if (rec.winDim.right < inset)
    {
      rec.winDim.left  = -((rec.winDim.right – rec.winDim.left) - inset);
      rec.winDim.right = inset;
    }

    if (rec.winDim.bottom < inset)
    {
      rec.winDim.top = -((rec.winDim.bottom – rec.winDim.top) - inset);
      rec.winDim.bottom = inset;
    }

Note. In certain cases, redundancy improves readability rather than hinders it. For example, it may help make mathematical formulas clearer. In such cases, suppressing false positives using one of the provided mechanisms is preferable to simplifying the expression.

This diagnostic is classified as:

CWE-682

You can look at examples of errors detected by the V1065 diagnostic.