Alvaro Herrera <alvherre@commandprompt.com> writes:
> David E. Wheeler wrote:
>> Why can't anyelement be freed from this constraint?
> Because it would break other uses of it, I think.
Specifically, what are you going to do with something like
make_array(anyelement, anyelement) returns anyarray
There's no principled way to determine what anyarray means if the
arguments are not the same type.
I have no objection to adding some other pseudotype with different
behavior, but breaking anyelement is not the path.
regards, tom lane