#21968·mypy

Exhaustiveness of type tuple[bool, bool]

Author: JulienPalardCreated Sep 11, 2026Updated Sep 13, 2026
Labelsbugtopic-match-statementtopic-reachability

Bug Report

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

To Reproduce

python
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