talloc: problem with talloc_steal usage from C++

[Volker Lendecke]

On Fri, Apr 13, 2012 at 12:32:24AM +0300, Jani Nikula wrote:
> Recently, an issue came up with using talloc_steal() in C++ code. For
> recent GCC, talloc.h has some macro magic to provide type safety for
> talloc_steal(). Otherwise, it returns a 'void *', which is okay to
> assign to a non-void pointer in C, but not in C++. An explicit cast
> would be required, losing the type safety for recent GCC, which is not
> very nice if you want to support both GCC and non-GCC compilers.
> 
> As a workaround in the notmuch project, I proposed [1]. Slightly hacky,
> but maintains type safety and does not require any changes in
> talloc_steal() callers. Now if this was done directly in talloc.h, it
> would not be hacky at all... *hint* ;)
> 
> It's a corner case in many ways, and talloc is a C library, so you may
> not be interested, but this is just to let you know such an issue
> exists.
> 
> [1] http://mid.gmane.org/1334264259-17632-1-git-send-email-jani@nikula.org

Not knowing C++ at all if this makes talloc more usable in
that language, you got my +1 if you replace the _notmuch_
with something more generic.

Volker

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