integer square root function proposed

Dear PostgreSQL colleagues:

I have just joined this, my first PG mailing list.

Reading the documentation I found no built-in function for integer square
root, requiring a sequence of:

floor(sqrt(foo))::integer

to go from an integer to the integer square root as an integer.

If PG leaders smile on this suggestion, could we have *isqrt*(foo) where
foo has a numeric type and the result type is the same numeric type, with
the result type being the integer square root for foo >= 0 and producing an
error if negative? (And with infinities and NaNs processed as described in
8.1 Numeric Types).

I did not see an explicit enhancement request list in the PG mailing lists.
Recommendations for a more specific list to post this to are welcome.

Sincerely,

Martin L. Buchanan
software developer
Laramie, WY, USA