varchar[N] interpreted as varchar, cannot detect exceeding column limit at compile time

[isosphere]

I have a PostgreSQL table with a varchar[N] column, where N is a fixed number. sqlx prepare detects this as a varchar, and I can accidentily exceed N when inserting into the column, even with a fixed string with a length known at compile time.

I guess we can't always catch this at compile time when using String inputs, because we won't know how long the string is until runtime, but it's a shame this class of error is completely undetectable at compile time at present.

Could we do better?