Ratio Parity trait

fixed_wide/src/fixed.rs

@@ -408,7 +408,12 @@ impl<const LHS_N:usize,const LHS_F:usize,const RHS_N:usize,const RHS_F:usize> co
 		ratio_ops::ratio::Ratio::new(self,other)
 	}
 }
-
+#[cfg(feature="deferred-division")]
+impl<const N:usize,const F:usize> ratio_ops::ratio::Parity for Fixed<N,F>{
+	fn parity(&self)->bool{
+		self.is_negative()
+	}
+}
 macro_rules! impl_shift_operator {
 	( $struct: ident, $trait: ident, $method: ident, $output: ty ) => {
 		impl<const N:usize,const F:usize> core::ops::$trait<u32> for $struct<N,F>{

ratio_ops/src/ratio.rs

@@ -68,17 +68,63 @@ impl_ratio_method!(Add,add,add_ratio);
 impl_ratio_method!(Sub,sub,sub_ratio);
 impl_ratio_method!(Rem,rem,rem_ratio);
 
+/// Comparing two ratios needs to know the parity of the denominators
+/// For signed integers this can be implemented with is_negative()
+pub trait Parity{
+	fn parity(&self)->bool;
+}
+macro_rules! impl_parity_unsigned{
+	($($type:ty),*)=>{
+		$(
+		impl Parity for $type{
+			fn parity(&self)->bool{
+				false
+			}
+		}
+		)*
+	};
+}
+macro_rules! impl_parity_signed{
+	($($type:ty),*)=>{
+		$(
+		impl Parity for $type{
+			fn parity(&self)->bool{
+				self.is_negative()
+			}
+		}
+		)*
+	};
+}
+macro_rules! impl_parity_float{
+	($($type:ty),*)=>{
+		$(
+		impl Parity for $type{
+			fn parity(&self)->bool{
+				self.is_sign_negative()
+			}
+		}
+		)*
+	};
+}
+
+impl_parity_unsigned!(u8,u16,u32,u64,u128,usize);
+impl_parity_signed!(i8,i16,i32,i64,i128,isize);
+impl_parity_float!(f32,f64);
+
 macro_rules! impl_ratio_ord_method{
 	($method:ident, $ratio_method:ident, $output:ty)=>{
-		impl<LhsNum,LhsDen> Ratio<LhsNum,LhsDen>{
+		impl<LhsNum,LhsDen:Parity> Ratio<LhsNum,LhsDen>{
 			#[inline]
-			pub fn $ratio_method<RhsNum,RhsDen,T>(self,rhs:Ratio<RhsNum,RhsDen>)->$output
+			pub fn $ratio_method<RhsNum,RhsDen:Parity,T>(self,rhs:Ratio<RhsNum,RhsDen>)->$output
 				where
 					LhsNum:core::ops::Mul<RhsDen,Output=T>,
 					LhsDen:core::ops::Mul<RhsNum,Output=T>,
 					T:Ord,
 			{
-				(self.num*rhs.den).$method(&(self.den*rhs.num))
+				match self.den.parity()^rhs.den.parity(){
+					true=>(self.den*rhs.num).$method(&(self.num*rhs.den)),
+					false=>(self.num*rhs.den).$method(&(self.den*rhs.num)),
+				}
 			}
 		}
 	}