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<overview>

<p>This rule finds code that uses

<code>x % 2 == 1</code>

to check whether a number <tt>x</tt> is odd, which does not work for negative numbers.

Applying <code>%</code> to negative numbers produces negative results.

For example, <code>(-5) % 2 </code> equals <code>-1</code>, not <code>1</code>.

As a result, this check incorrectly considers all negative numbers as even.

</p>

</overview>

<recommendation>

<p>Consider using

<code>x % 2 != 0</code> or <code>(x &amp; 1) == 1</code> instead.

</p>

</recommendation>

<references>

<li>

MSDN Library: <a href="https://docs.microsoft.com/en-us/cpp/cpp/multiplicative-operators-and-the-modulus-operator">Multiplicative Operators and the Modulus Operator</a>.

</li>

<li>

Wikipedia: <a href="http://en.wikipedia.org/wiki/Modulo_operation#Common_pitfalls">Modulo Operation - Common pitfalls</a>.

</li>

</references>

</qhelp>