pgsql: Support using copyObject in standard C++

Started by Peter Eisentraut5 months ago1 messagescomitters

peter_e@gmx.net

5 months ago

Support using copyObject in standard C++

Calling copyObject in C++ without GNU extensions (e.g. when using
-std=c++11 instead of -std=gnu++11) fails with an error like this:

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

This is due to the C compiler used to compile PostgreSQL supporting
typeof, but that function actually not being present in the C++
compiler. This fixes that by explicitely checking for typeof support
in C++, and then either use that or define typeof ourselves as:

std::remove_reference_t<decltype(x)>

According to the paper that led to adding typeof to the C standard,
that's the C++ equivalent of the C typeof:
https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2927.htm#existing-decltype

Author: Author: Jelte Fennema-Nio <postgres@jeltef.nl>
Discussion: /messages/by-id/DGPW5WCFY7WY.1IHCDNIVVT300@jeltef.nl

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/1887d822f1428637c935b9f5e8be4a2a56fb77c7