WideMul trait

Cargo.lock

@@ -58,6 +58,7 @@ version = "0.1.0"
 dependencies = [
  "bnum",
  "fixed",
+ "typenum",
 ]
 
 [[package]]

fixed_wide/Cargo.lock

@@ -50,6 +50,7 @@ version = "0.1.0"
 dependencies = [
  "bnum",
  "fixed",
+ "typenum",
 ]
 
 [[package]]

fixed_wide/Cargo.toml

@@ -6,3 +6,4 @@ edition = "2021"
 [dependencies]
 bnum = "0.11.0"
 fixed = "1.28.0"
+typenum = "1.17.0"

fixed_wide/src/wide.rs

@@ -1,4 +1,30 @@
-pub struct Fixed<I,Frac>{
-	bits:I,
+use bnum::types::{I256,I512};
+use fixed::{FixedI64,FixedI128};
+use typenum::{Sum, Unsigned};
+use typenum::consts::{U32,U64,U96,U128,U160,U192,U224,U256};
+
+pub trait WideMul<Rhs=Self>{
+	type Output;
+	fn wide_mul(self,rhs:Rhs)->Self::Output;
+}
+
+pub struct Fixed<Int,Frac>{
+	bits:Int,
 	phantom:std::marker::PhantomData<Frac>,
 }
+pub type FixedI256<Frac>=Fixed<I256,Frac>;
+pub type FixedI512<Frac>=Fixed<I512,Frac>;
+
+impl<A,B> WideMul<FixedI128<B>> for FixedI128<A>
+	where
+		A:std::ops::Add<B>,
+		B:Unsigned,
+{
+	type Output=FixedI256<Sum<A,B>>;
+	fn wide_mul(self,rhs:FixedI128<B>)->Self::Output{
+		FixedI256{
+			bits:I256::from(self.to_bits())*I256::from(rhs.to_bits()),
+			phantom:std::marker::PhantomData,
+		}
+	}
+}