fn() popCountReturns number of set bits in an integer.
Returns number of set bits in an integer.
Defined in  <seqan/misc/bit_twiddling.h> 

Signature 
unsigned popCount(words);

Parameters
word

The word to count the number of set bits of (IntegerConcept). 

Return Values
unsigned 
The number of set bits in word. 

Data Races
If not stated otherwise, concurrent invocation is not guaranteed to be threadsafe.