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List:       kde-commits
Subject:    Re: KDE/kdepim/plugins/kmail/bodypartformatter
From:       David Faure <dfaure () kdab ! net>
Date:       2008-02-18 11:11:28
Message-ID: 200802181211.31982.dfaure () kdab ! net
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On Sunday 17 February 2008, Ingo Klöcker wrote:
> On Saturday 16 February 2008, Till Adam wrote:
> > +      const QString addedLineStyle( "style=\"" "color: green;\"" );
> 
> Why is this a QString while everything else is a QLatin1String?
> 
> And wouldn't it make sense to make those static const so that they are 
> constructed only once? I guess it doesn't really matter because the 
> c'tor of QLatin1String is dead-cheap, but it might serve as example for 
> other usages of constants.

This looks like funny optimization "lookalike" to me.

text_xdiff.cpp:      static const QLatin1String tableStyle(
Very fast, whether static or not.

text_xdiff.cpp:      html += "<pre " + tableStyle + '>';
Slow anyway, has to convert the QLatin1String to a QString at that point.

QLatin1String saves you time only when you are comparing with it, not when you are \
going to assign from it...

All those strings are used only once so it doesn't matter, but if they were used more \
than  once then making them QString in the first place would actually be faster :-)

Oh well, no big deal, just a common misconception about QLatin1String IMHO.

-- 
David Faure, faure@kde.org, dfaure@klaralvdalens-datakonsult.se
KDE/KOffice developer, Qt consultancy projects
Klarälvdalens Datakonsult AB, Platform-independent software solutions


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