[Development] QForeachContainer mystery

[Joerg Bornemann]

Consider the following piece of code:

QStringList other;
foreach (QString str, QStringList(other))
     ;    // do something

This builds fine with Visual Studio 2013.

With gcc 4.7.2 and clang 3.0-6.2 we get:
error: request for member 'brk' in '_container_', which is of non-class 
type 'QForeachContainer<QStringList>(QStringList)'

To trigger this compile error it's enough to do

QStringList other;
QForeachContainer<__typeof__(QStringList(other))> 
_container_(QStringList(other));
_container_.brk = 0;


Interestingly, one can work around this error by wrapping the c'tor with 
a function or passing a variable to foreach.

----
QStringList id(QStringList x) { return x; }
...
QStringList other;
foreach (QString str, id(QStringList(other)))
     ;    // do something
----
QStringList other;
QStringList troz(other);
foreach (QString str, troz)
     ;    // do something
----

Looks like __typeof__, which is used when building with a recent gcc, 
behaves differently when passing a c'tor?
Could anyone shed light on this mystery?


Cheers,

Joerg

P.S. Yeeees it's quite pointless to use a copy constructor like this in 
foreach. The example above is artifical. :)