[Development] QTextStream::readLine(0) is an ambiguous overload in 5.5

[André Pönitz]

On Wed, May 13, 2015 at 09:44:40AM +0900, Thiago Macieira wrote:
> On Wednesday 13 May 2015 02:34:28 Jan Kundrát wrote:
> > Hi,
> > this commit [1] added a new overload to QTextStream::readLine. As a result
> > of that, calling stream.readLine(0) is now ambiguous:
> > 
> >     QString readLine(qint64 maxlen = 0);
> >     bool readLine(QString *line, qint64 maxlen = 0);
> > 
> > While I can easily fix this in the caller (Konsole in this case), I'm
> > wodnering whether this effect was understood at the time the change was
> > merged. IMHO it's a bit more user-friendly to preserve source compatibility
> > by removing the default value in the newly added overload.
> > 
> > Should I send such a patch?
> 
> Why write readLine(0) when it's the same as readLine() ? readLine(0) seems to 
> me that it's asking for a line of at most zero bytes -- we should have had 
> this argument default to -1 to indicate maximum length, not 0.
> 
> Removing the default argument for the new overload will make it worse, by 
> making people have to write the zero when they mean unlimited. I don't like 
> that. The two options I will consider are:
> 
> a) do nothing, accept and document the source incompatibility
> b) modify differently so that the new API isn't ambiguous but doesn't require 
> people to write 0 either.

Does it have to be an *overload*?

Andre'