Performance improvement

[Thiago Macieira]

On Thursday, 22 May 2025 11:21:03 Central Daylight Time Igor Mironchik wrote:
> 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?

In addition to what other people have said, the problem here is that your 
predicate depends on Unicode attributes. Even though the set is limited and 
closed, it isn't known at compile time. In fact, considering Qt can be updated 
without the application, it will only be known at runtime.

Specifically for spaces, maybe you should consider QString::trimmed(), which 
can access the unicode tables directly and thus avoids the overhead of a 
function call.

-- 
Thiago Macieira - thiago (AT) macieira.info - thiago (AT) kde.org
  Principal Engineer - Intel Platform & System Engineering