Performance improvement

[Igor Mironchik]

Hi.

I'd like to ask you, guys, maybe I'm a dumb a little, and you know how 
to optimize a following function.

inline long long int
skipIf(long long int startPos, const QString &line,
        const std::function<bool(const QChar &)> &pred,
        long long int endPos = -1)
{
     const auto length = (endPos < line.length() && endPos > -1 ? endPos 
: line.length());

     while (startPos < length && pred(line[startPos])) {
         ++startPos;
     }

     return startPos;
}

This function is needed to walk through the string with some predicate. 
It's needed in some cases. I know that QString::indexOf(QChar) is very 
efficient, but consider I need to skip all QChar::isSpace()... 
QString::indexOf() won't help in this situation, but skipIf() with 
predicate is very helpful here. For example.

inline long long int
skipSpaces(long long int i, const QString &line)
{
     return skipIf(i, line, [](const QChar &ch){ return ch.isSpace(); });
}

Do you know a way to optimize it?

Thank you.