MIME-Version: 1.0
From: Jelte Fennema-Nio <postgres@jeltef.nl>
Date: Fri, 5 Dec 2025 15:46:57 +0100
Message-ID: 
 <CAGECzQR21OnnKiZO_1rLWO0-16kg1JBxnVq-wymYW0-_1cUNtg@mail.gmail.com>
Subject: Make copyObject work in C++
To: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>,
	Thomas Munro <thomas.munro@gmail.com>
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Calling copyObject fails in C++ with an error like in most setups:

error: use of undeclared identifier 'typeof'; did you mean 'typeid'

This is due to the C compiler supporting used to compile postgres
supporting typeof, but that function actually not being present in the
C++ compiler. This fixes that by using decltype instead of typeof when
including the header in C++.

Realized because of Thomas' not about how much of our headers should
work in C++, and remembering I hit this specific problem myself.

Another approach would be to force the value of HAVE_TYPEOF to 0 if __cplusplus.

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