Re: Make copyObject work in C++

Jelte Fennema <postgres@jeltef.nl>

From: Jelte Fennema-Nio <postgres@jeltef.nl>
To: Peter Eisentraut <peter@eisentraut.org>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Thomas Munro <thomas.munro@gmail.com>, Andres Freund <andres@anarazel.de>
Date: 2026-03-31T09:09:59Z
Lists: pgsql-hackers
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.



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