c-style-math-functions.qhelp

<!DOCTYPE qhelp PUBLIC
  "-//Semmle//qhelp//EN"
  "qhelp.dtd">
<qhelp>

<overview>
<p>The C++ standard library provides a large selection of math functions.
These functions are available for use either in the std namespace or in the global namespace.</p>

<p>In order to highlight invocations of the standard library and avoid occasional
definitional differences of these functions, we prefer to avoid use of the functions in the global namespace.</p>

</overview>
<recommendation>

<p>Prefer to invoke the functions defined in the std namespace.</p>

</recommendation>
<example>

<p>Most current c++ standard libraries will allow invoking math functions in the global namespace</p>
<sample language="cpp">
#include &lt;cmath&gt;

float my_pow( float base, float exp ) {
    return pow( base, exp );
}
</sample>

<p>Prefer invoking the version in the std namespace.</p>
<sample language="cpp">
#include &lt;cmath&gt;

float my_pow( float base, float exp ) {
    return std::pow( base, exp );
}
</sample>

</example>
<references>

<li>
  Informative Stack Exchange Answer:
  <a href="https://stackoverflow.com/a/8734292/280690">Differences between math.h and cmath</a>.
</li>

</references>
</qhelp>