Exhaustiveness of type tuple[bool, bool]

[JulienPalard]

Bug Report

It looks like the exhaustiveness of tuples of bools is not checked in match statements.

To Reproduce

def measure(a: bool, b: bool) -> float:
    match a, b:
        case True, True:
            return 1
        case True, False:
            return 0.9
        case False, True:
            return 0.5
        case False, False:
            return 0

Expected Behavior

Should pass, looks exhaustive to me (or I should go take a nap).

Actual Behavior

$ mypy --enable-error-code exhaustive-match repro.py
repro.py:1: error: Missing return statement  [return]
repro.py:2: error: Match statement has unhandled case for values of type "tuple[bool, bool]"  [exhaustive-match]
repro.py:2: note: If match statement is intended to be non-exhaustive, add `case _: pass`
Found 2 errors in 1 file (checked 1 source file)

Your Environment

• Mypy version used: mypy 2.3.1 (compiled: yes)
• Mypy command-line flags: --enable-error-code exhaustive-match
• Mypy configuration options from mypy.ini (and other config files): ø
• Python version used: 3.14.7

[EmmanuelNiyonshuti]

This is probably related to #16722

in case it helps, assert_never for this repro reproduces identically:

def measure(a: bool, b: bool) -> float:
    match a, b:
        case True, True:
            return 1
        case True, False:
            return 0.9
        case False, True:
            return 0.5
        case False, False:
            return 0
        case _ as never:
            #error: Argument 1 to "assert_never" has incompatible type "tuple[bool, bool]"; expected "Never"  [arg-type]
            assert_never(never)