Automatic using ::rtl::OUString etc.

[Bjoern Michaelsen]

On Fri, Apr 13, 2012 at 08:21:35AM +0200, Stephan Bergmann wrote:
> On 04/12/2012 03:59 PM, Lubos Lunak wrote:
> >  would somebody see a problem with this?
> >
> >sal/inc/rtl/ustring.hxx :
> >+#ifdef RTL_AUTOMATIC_USING
> >+using ::rtl::OUString;
> >+using ::rtl::OStringToOUString;
> >+using ::rtl::OUStringToOString;
> >+#endif
> 
> I am not too excited about this.
> 
> For one, we need to ensure that none of the URE published interface
> implicitly relies on -DRTL_AUTOMATIC_USING.  (And it is not clear to
> me that compiling the sal library with -URTL_AUTOMATIC_USING could
> even catch all problems in sal headers.)
> 
> For another, it increases accidental complexity (an ifdef block; yet
> another -D always passed in) for IMO little gain.
> 
> And for a third, it introduces a magic special case (certain names
> from the rtl namespace can be used without qualification; without
> this being evident from the C++ source code itself, as it relies on
> .mk file behavior; but there is an exception, that this special case
> must not be used in certain headers).

I tend to agree on all points. If something like that is essential, we could
have something like a:
salhelper/inc/rtl/stringhelper.hxx:
#include <rtl/ustring.hxx>
using ::rtl::OUString;
using ::rtl::OStringToOUString;
using ::rtl::OUStringToOString;

and allow that to be used in .cxx only but not in .hxx. Then again the gain is
limited by that and its not automatically checkable without some ugly extra
scripting (right?).

Best,

Bjoern