Refactor Uint::{concat, concat_mixed}

src/uint/concat.rs

@@ -1,34 +1,45 @@
 use crate::{Concat, ConcatMixed, Limb, Uint};
 
-impl<T> Concat for T
-where
-    T: ConcatMixed<T>,
-{
-    type Output = Self::MixedOutput;
-}
+impl<const L: usize> Uint<L> {
+    /// Concatenate the two values, with `self` as least significant and `hi` as the most
+    /// significant.
+    pub const fn concat<const O: usize>(&self, hi: &Self) -> Uint<O>
+    where
+        Self: Concat<Output = Uint<O>>,
+    {
+        Uint::concat_mixed(self, hi)
+    }
 
-/// Concatenate the two values, with `lo` as least significant and `hi`
-/// as the most significant.
-#[inline]
-pub(crate) const fn concat_mixed<const L: usize, const H: usize, const O: usize>(
-    lo: &Uint<L>,
-    hi: &Uint<H>,
-) -> Uint<O> {
-    let top = L + H;
-    let top = if top < O { top } else { O };
-    let mut limbs = [Limb::ZERO; O];
-    let mut i = 0;
+    /// Concatenate the two values, with `lo` as least significant and `hi`
+    /// as the most significant.
+    #[inline]
+    pub const fn concat_mixed<const H: usize, const O: usize>(lo: &Uint<L>, hi: &Uint<H>) -> Uint<O>
+    where
+        Self: ConcatMixed<Uint<H>, MixedOutput = Uint<O>>,
+    {
+        let top = L + H;
+        let top = if top < O { top } else { O };
+        let mut limbs = [Limb::ZERO; O];
+        let mut i = 0;
 
-    while i < top {
-        if i < L {
-            limbs[i] = lo.limbs[i];
-        } else {
-            limbs[i] = hi.limbs[i - L];
+        while i < top {
+            if i < L {
+                limbs[i] = lo.limbs[i];
+            } else {
+                limbs[i] = hi.limbs[i - L];
+            }
+            i += 1;
         }
-        i += 1;
+
+        Uint { limbs }
     }
+}
 
-    Uint { limbs }
+impl<T> Concat for T
+where
+    T: ConcatMixed<T>,
+{
+    type Output = Self::MixedOutput;
 }
 
 #[cfg(test)]

src/uint/macros.rs

@@ -83,7 +83,7 @@ macro_rules! impl_uint_concat_split_mixed {
             type MixedOutput = $name;
 
             fn concat_mixed(&self, hi: &Uint<{ U64::LIMBS * $size }>) -> Self::MixedOutput {
-                $crate::uint::concat::concat_mixed(self, hi)
+                Uint::concat_mixed(self, hi)
             }
         }
 
@@ -113,15 +113,7 @@ macro_rules! impl_uint_concat_split_even {
             type MixedOutput = $name;
 
             fn concat_mixed(&self, hi: &Uint<{ <$name>::LIMBS / 2 }>) -> Self::MixedOutput {
-                $crate::uint::concat::concat_mixed(self, hi)
-            }
-        }
-
-        impl Uint<{ <$name>::LIMBS / 2 }> {
-            /// Concatenate the two values, with `self` as least significant and `hi` as the most
-            /// significant.
-            pub const fn concat(&self, hi: &Uint<{ <$name>::LIMBS / 2 }>) -> $name {
-                $crate::uint::concat::concat_mixed(self, hi)
+                Uint::concat_mixed(self, hi)
             }
         }
 

src/uint/mul.rs

@@ -2,7 +2,6 @@
 
 // TODO(tarcieri): use Karatsuba for better performance
 
-use super::concat::concat_mixed;
 use crate::{
     Checked, CheckedMul, Concat, ConcatMixed, Limb, Uint, WideningMul, Wrapping, WrappingMul, Zero,
 };
@@ -61,10 +60,10 @@ impl<const LIMBS: usize> Uint<LIMBS> {
         rhs: &Uint<RHS_LIMBS>,
     ) -> Uint<WIDE_LIMBS>
     where
-        Uint<RHS_LIMBS>: ConcatMixed<Self, MixedOutput = Uint<WIDE_LIMBS>>,
+        Self: ConcatMixed<Uint<RHS_LIMBS>, MixedOutput = Uint<WIDE_LIMBS>>,
     {
         let (lo, hi) = self.split_mul(rhs);
-        concat_mixed(&lo, &hi)
+        Uint::concat_mixed(&lo, &hi)
     }
 
     /// Compute "wide" multiplication as a 2-tuple containing the `(lo, hi)` components of the product, whose sizes
@@ -172,7 +171,7 @@ where
     /// Square self, returning a concatenated "wide" result.
     pub const fn square(&self) -> Uint<WIDE_LIMBS> {
         let (lo, hi) = self.square_wide();
-        concat_mixed(&lo, &hi)
+        lo.concat(&hi)
     }
 }
 
@@ -244,9 +243,9 @@ impl<const LIMBS: usize> MulAssign<&Checked<Uint<LIMBS>>> for Checked<Uint<LIMBS
 impl<const LIMBS: usize, const RHS_LIMBS: usize, const WIDE_LIMBS: usize>
     WideningMul<Uint<RHS_LIMBS>> for Uint<LIMBS>
 where
-    Uint<RHS_LIMBS>: ConcatMixed<Self, MixedOutput = Uint<WIDE_LIMBS>>,
+    Self: ConcatMixed<Uint<RHS_LIMBS>, MixedOutput = Uint<WIDE_LIMBS>>,
 {
-    type Output = <Uint<RHS_LIMBS> as ConcatMixed<Self>>::MixedOutput;
+    type Output = <Self as ConcatMixed<Uint<RHS_LIMBS>>>::MixedOutput;
 
     #[inline]
     fn widening_mul(&self, rhs: Uint<RHS_LIMBS>) -> Self::Output {
@@ -257,9 +256,9 @@ where
 impl<const LIMBS: usize, const RHS_LIMBS: usize, const WIDE_LIMBS: usize>
     WideningMul<&Uint<RHS_LIMBS>> for Uint<LIMBS>
 where
-    Uint<RHS_LIMBS>: ConcatMixed<Self, MixedOutput = Uint<WIDE_LIMBS>>,
+    Self: ConcatMixed<Uint<RHS_LIMBS>, MixedOutput = Uint<WIDE_LIMBS>>,
 {
-    type Output = <Uint<RHS_LIMBS> as ConcatMixed<Self>>::MixedOutput;
+    type Output = <Self as ConcatMixed<Uint<RHS_LIMBS>>>::MixedOutput;
 
     #[inline]
     fn widening_mul(&self, rhs: &Uint<RHS_LIMBS>) -> Self::Output {