id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
10985	Logically dead code; dubious source code comment / inverted if condition?	Jonas Maaskola <jonas@…>	John Maddock	"Static code analysis with Coverity pointed me to some dead code in the function ibeta_imp in boost/math/special_functions/beta.hpp.
My system's boost library is 1.55.0, but the issue is present identically in boost 1.57.
In a block guarded by
{{{
if (normalised) {
}}}
there is the following line (number 1224):
{{{
               fract -= (normalised ? 1 : boost::math::beta(a, b, pol));
}}}
Clearly, normalised has to be true due to the if guard thus the second part (boost::math::beta(a, b, pos)) will never be used.

Furthermore, it may be that the if guard's condition is missing a negation for which there are two indications:
 * in the vicinity (i.e. in the function ibeta_imp) most other if statements (6 of 7) that involve normalised check if normalised is not set (i.e. ""if(!normalised)""), and
 * more importantly, the first comment in that block on lines 1211-1213 reads:
{{{
1209:         else if(normalised)
1210:         {
1211:            // the formula here for the non-normalised case is tricky to figure
1212:            // out (for me!!), and requires two pochhammer calculations rather
1213:            // than one, so leave it for now....
}}}
I apologize for my limited understanding of the details of the code, which precludes me from proposing a fix, but something seems fishy here!

Finally, the line subsequent to the one with the dead code, i.e. line 1225, contains a commented-out alternative. This indicates to me that this entire block may not have been fully satisfactory to the original author(s)."	Bugs	closed	To Be Determined	math	Boost 1.57.0	Problem	fixed