Feature request: Changes in Unique constraint / Unique Index

From the manual:

The constraint allows existence of only those rows for which the
aforementioned <search condition>
evaluates to True. In a unique index or under a UNIQUE constraint, two
sets of column values will be
considered distinct and thus allowed if:
a) both sets contain only nulls, or
b) there is at least one pair of corresponding values of which one is
non-null, and the other either null
or a different non-null value.
.
.
.

What I would like is that two or more sets of column values will be
considered distinct and thus allowed if: at least one contains nulls.

After all isn't it safe to say that (1,null) is distinct from (1,null) as
long as null is distinct from null ?


best regards
Trond.
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