infallible narrow tosses fractional bits and has the same or greater integer bits

fixed_wide/src/narrow.rs

@@ -34,4 +34,17 @@ mod tests {
 		assert!(matches!(64i16.try_narrow(),Ok(64i8)));
 		assert!(matches!((-257i16).try_narrow(),Err(NarrowError::Underflow)));
 	}
+
+	impl Narrow for fixed::FixedI16<typenum::consts::U8>{
+		type Output=i8;
+		fn narrow(self)->Self::Output{
+			(self.to_bits()>>8) as i8
+		}
+	}
+
+	#[test]
+	fn test_fixed_i16_i8(){
+		let a=fixed::FixedI16::<typenum::consts::U8>::from(5)/2;
+		assert_eq!(a.narrow(),2);
+	}
 }