Re: Make copyObject work in C++

Peter Eisentraut <peter@eisentraut.org>

From: Peter Eisentraut <peter@eisentraut.org>
To: Jelte Fennema-Nio <postgres@jeltef.nl>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Thomas Munro <thomas.munro@gmail.com>, Andres Freund <andres@anarazel.de>
Date: 2026-04-01T05:54:07Z
Lists: pgsql-hackers
On 31.03.26 11:09, Jelte Fennema-Nio wrote:
> On Tue, 31 Mar 2026 at 10:33, Peter Eisentraut <peter@eisentraut.org> wrote:
>> Hmm, note that C++ is also used for LLVM/JIT, and by requiring this
>> additional feature set we are also imposing new requirements for those
>> users.  This has not been fully explored, and I hesitate to add such a
>> new requirement at the last moment.
> 
> I understand the hesitation, but in practice we already impose those
> requirements anyway for non-MSVC compilers because test_cplusplusext
> doesn't compile without it. So any compiler that would cause problems
> with the new featureset would have already complained about that
> before.
> 
>> But how about this: We add the feature test that you propose and enable
>> the extension based on that.  See attached patch.  This reduces to
>> essentially a three-line patch, much simpler than all previous proposals.
> 
> If you're still worried, then this sounds like a fine middle-ground
> for now. I think we should reconsider adding the automatic /std:c++20
> flag for the PG20 dev cycle though.

Ok, I have committed the shown patch.




Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →
  1. Enable test_cplusplusext with MSVC

  2. Disable some C++ warnings in MSVC

  3. meson: Make room for C++-only warning flags for MSVC

  4. Make fixed-length list building macros work in C++

  5. Make unconstify and unvolatize use StaticAssertVariableIsOfTypeMacro

  6. Use typeof everywhere instead of compiler specific spellings

  7. Test List macros in C++ extensions

  8. Test most StaticAssert macros in C++ extensions

  9. Revert "Change copyObject() to use typeof_unqual"

  10. Fix for C++ compatibility

  11. tests: Add a test C++ extension module