message: InputGenerator: value() return type fix.
diff: @@ -30,7 +30,7 @@ class Modifier {
  constexpr Modifier(Key _key) : mask_{static_cast<unsigned>(_key)} {}
  - constexpr bool value() const noexcept { return mask_; }
  + constexpr unsigned value() const noexcept { return mask_; }
  constexpr bool none() const noexcept { return value() == 0; }
  constexpr bool shift() const noexcept { return value() & Shift; }
  