Any boolean expression is capable of being short-circuited, in the right circumstances.
So under what circumstances can you short-circuit an XOR? (i.e, if either A or B but not both then C)?
T-SQL lacks a XOR logical operator, but it can be implemented from its definition:
A XOR B = (A AND NOT B) OR (NOT A AND B)
Sorry for the stupid example, I can't think of a better one right now: to find all users with NULL first_name (expression A) or NULL middle_name (expression B) but not both you could write:
-- This is how you would do it if T-SQL had a XOR operator.
WHERE (first_name IS NULL) XOR (middle_name IS NULL)
-- This is how you have to code it with AND, OR and NOT operators
WHERE (first_name IS NULL AND middle_name IS NOT NULL)
OR (first_name IS NOT NULL AND middle_name IS NULL)
Any boolean operator can be rewritten using AND, OR and NOT.