Same issue applies to the >> operator as well.

operator>>(str) is impossible to implement because strings are immutable
objects in python, use readString instead.

Ah, so true! Just ran across those while fixing the examples and didn't think
too far.

In any case, both the << and >> operators in Python are so horribly ugly that
it's hard to think anyone could have implemented them in the first place...

Just lifting up the ball: Why to removing them?

I meant, why not removing them? :)

(In reply to comment #5)
> I meant, why not removing them? :)

I guess it's a bit late now, would break lots of existing functionality.
Perfect content for PySide 2, IMHO. :-)

Current test covers <</>> usage with

QByteArray
QBitArray
QDate
QTime
QDateTime.

The current software uses writeInt, writeQString for them.

The issue still exists and there might be software using the horrible << syntax
- bumping to P4.

I mean, like this.

I'm raising this to P3 - this could well be fixed before 1.0.

Matti, there some problems in operator<< and operator>> for QDataStream:

operator>> is only possible for mutable objects, i.e. not integers or strings.

operator<<has the following problem:

As QDataStream is used to create a binary stream all those operator overloads
produces different behavious:

operator<<(unsigned int)
operator<<(unsigned short)
operator<<(int)
operator<<(short)
operator<<(long)
operator<<(unsigned long)

Python has just two kind of numbers, int and long, so when the Python user
writes:

s = QDataStream()
s << 2

We have no enough info to discover what version of operator<< should be called,
this is why we have the writeInt32, writeInt16, writeUInt16 like PyQt.

On the typesystem we only remove the operator<< and operator>> for number
types, so it still working for things like QDate, QTime etc as I checked:

In [19]: data = QByteArray()

In [20]: c
Out[20]: <PySide.QtGui.QColor(ARGB 1, 0, 0, 1)  at 0x1e82968>

In [21]: d
Out[21]: <PySide.QtGui.QColor(Invalid)  at 0x1e82148>

In [22]: s = QDataStream(data, QIODevice.WriteOnly)

In [23]: s << c
Out[23]: <PySide.QtCore.QDataStream object at 0x1e82a30>

In [24]: data.size()
Out[24]: 11

In [25]: del s

In [26]: data.size()
Out[26]: 11

In [27]: s = QDataStream(data, QIODevice.ReadOnly)

In [28]: d
Out[28]: <PySide.QtGui.QColor(Invalid)  at 0x1e82148>

In [29]: s >> d
Out[29]: <PySide.QtCore.QDataStream object at 0x1e82580>

In [30]: d
Out[30]: <PySide.QtGui.QColor(ARGB 1, 0, 0, 1)  at 0x1e82148>


So I need to know what operator<</operator>> overload is missing, despite of
the ones using numbers.

(In reply to comment #11)

> operator>> is only possible for mutable objects, i.e. not integers or strings.

Yes, that's obvious. :-)


> Python has just two kind of numbers, int and long, so when the Python user
> writes:
> 
> s = QDataStream()
> s << 2
> 
> We have no enough info to discover what version of operator<< should be called,
> this is why we have the writeInt32, writeInt16, writeUInt16 like PyQt.

OK, I see the problem. So, maybe the best approach would be to treat the
operators deprecated?

However, I still think this is a valid bug: string serialization using the <<
operator should probably work. If you run the example and see the resulting
file, you'll see the issue. So, disregard the silly comment regarding the >>
operator, but try out the sample code. :-)

(In reply to comment #12)
> OK, I see the problem. So, maybe the best approach would be to treat the
> operators deprecated?
> 
> However, I still think this is a valid bug: string serialization using the <<
> operator should probably work. If you run the example and see the resulting
> file, you'll see the issue. So, disregard the silly comment regarding the >>
> operator, but try out the sample code. :-)

I just tried with PySide from git HEAD
(c7b5d3ed9e9ca0c1c76b3e9b0830337c4b03c88e) and it works :-)

Closed due to release of 1.0.0~beta4