Re: Why do we test a build using g++?

On Sat, Jul 04, 2026 at 04:44:47PM -0600, Karl Williamson via perl5-porters wrote:
> I've harbored some ambitions to convert portions of the core to be written
> in C++.
> 
> Can someone explain why Topaz (which attempted something like this) failed
> or post a link.
> 
> Have events moved on so the languages are too disparate for this to be
> feasible?

The languages are used very differently.

I do think some things could be done more simply if Perl were C++, I
know you've come across a few cases where you've needed to mortalize
an SV (AV, whatever) that you're planning on returning because
something you call may throw an exception.

If we used C++ you could use RAII to ensure the SV was released on an
exception, and disarm that for the normal return path, vaguely like:

  // like std::unique_ptr
  unique_sv s = newAV();
  ... stuff that might throw ...
  return s.release();

but RAII is incompatible with the way Perl handles exceptions -
longjmp() bypassing such cleanup is undefined behaviour, and replacing
setjmp()/longjmp() with C++ exceptions would break XS code that uses
the older style exceptions.

RAII is such a basic concept in C++ I don't see any point in changing
to C++ without it.

Tony