boost::algorithm::trim_all_if — Trim All.
// In header: <boost/algorithm/string/trim_all.hpp> template<typename SequenceT, typename PredicateT> void trim_all_if(SequenceT & Input, PredicateT IsSpace);
Remove all leading and trailing spaces from the input and compress all other spaces to a single character. The input sequence is modified in-place.
Parameters:
Input
An input sequence
IsSpace
A unary predicate identifying spaces