Try splitting part of 'Int' into 'MinInt' so we don't need to impleme…

…nt everything on u256/i256

src/float/add.rs

@@ -1,5 +1,5 @@
 use crate::float::Float;
-use crate::int::{CastInto, Int};
+use crate::int::{CastInto, Int, MinInt};
 
 /// Returns `a + b`
 fn add<F: Float>(a: F, b: F) -> F
@@ -57,17 +57,17 @@ where
         }
 
         // zero + anything = anything
-        if a_abs == Int::ZERO {
+        if a_abs == MinInt::ZERO {
             // but we need to get the sign right for zero + zero
-            if b_abs == Int::ZERO {
+            if b_abs == MinInt::ZERO {
                 return F::from_repr(a.repr() & b.repr());
             } else {
                 return b;
             }
         }
 
         // anything + zero = anything
-        if b_abs == Int::ZERO {
+        if b_abs == MinInt::ZERO {
             return a;
         }
     }
@@ -113,10 +113,10 @@ where
     // Shift the significand of b by the difference in exponents, with a sticky
     // bottom bit to get rounding correct.
     let align = a_exponent.wrapping_sub(b_exponent).cast();
-    if align != Int::ZERO {
+    if align != MinInt::ZERO {
         if align < bits {
             let sticky =
-                F::Int::from_bool(b_significand << bits.wrapping_sub(align).cast() != Int::ZERO);
+                F::Int::from_bool(b_significand << bits.wrapping_sub(align).cast() != MinInt::ZERO);
             b_significand = (b_significand >> align.cast()) | sticky;
         } else {
             b_significand = one; // sticky; b is known to be non-zero.
@@ -125,8 +125,8 @@ where
     if subtraction {
         a_significand = a_significand.wrapping_sub(b_significand);
         // If a == -b, return +zero.
-        if a_significand == Int::ZERO {
-            return F::from_repr(Int::ZERO);
+        if a_significand == MinInt::ZERO {
+            return F::from_repr(MinInt::ZERO);
         }
 
         // If partial cancellation occured, we need to left-shift the result
@@ -143,8 +143,8 @@ where
 
         // If the addition carried up, we need to right-shift the result and
         // adjust the exponent:
-        if a_significand & implicit_bit << 4 != Int::ZERO {
-            let sticky = F::Int::from_bool(a_significand & one != Int::ZERO);
+        if a_significand & implicit_bit << 4 != MinInt::ZERO {
+            let sticky = F::Int::from_bool(a_significand & one != MinInt::ZERO);
             a_significand = a_significand >> 1 | sticky;
             a_exponent += 1;
         }
@@ -160,7 +160,7 @@ where
         // need to shift the significand.
         let shift = (1 - a_exponent).cast();
         let sticky =
-            F::Int::from_bool((a_significand << bits.wrapping_sub(shift).cast()) != Int::ZERO);
+            F::Int::from_bool((a_significand << bits.wrapping_sub(shift).cast()) != MinInt::ZERO);
         a_significand = a_significand >> shift.cast() | sticky;
         a_exponent = 0;
     }

src/float/cmp.rs

@@ -1,7 +1,7 @@
 #![allow(unreachable_code)]
 
 use crate::float::Float;
-use crate::int::Int;
+use crate::int::{Int, MinInt};
 
 #[derive(Clone, Copy)]
 enum Result {

src/float/div.rs

@@ -3,7 +3,7 @@
 #![allow(clippy::needless_return)]
 
 use crate::float::Float;
-use crate::int::{CastInto, DInt, HInt, Int};
+use crate::int::{CastInto, DInt, HInt, Int, MinInt};
 
 fn div32<F: Float>(a: F, b: F) -> F
 where

src/float/extend.rs

@@ -1,5 +1,5 @@
 use crate::float::Float;
-use crate::int::{CastInto, Int};
+use crate::int::{CastInto, Int, MinInt};
 
 /// Generic conversion from a narrower to a wider IEEE-754 floating-point type
 fn extend<F: Float, R: Float>(a: F) -> R

src/float/mod.rs

@@ -1,6 +1,6 @@
 use core::ops;
 
-use super::int::Int;
+use super::int::{Int, MinInt};
 
 pub mod add;
 pub mod cmp;

src/float/mul.rs

@@ -1,5 +1,5 @@
 use crate::float::Float;
-use crate::int::{CastInto, DInt, HInt, Int};
+use crate::int::{CastInto, DInt, HInt, Int, MinInt};
 
 fn mul<F: Float>(a: F, b: F) -> F
 where

src/float/trunc.rs

@@ -1,5 +1,5 @@
 use crate::float::Float;
-use crate::int::{CastInto, Int};
+use crate::int::{CastInto, Int, MinInt};
 
 fn trunc<F: Float, R: Float>(a: F) -> R
 where

src/int/addsub.rs

@@ -1,6 +1,6 @@
-use crate::int::{DInt, Int};
+use crate::int::{DInt, Int, MinInt};
 
-trait UAddSub: DInt {
+trait UAddSub: DInt + Int {
     fn uadd(self, other: Self) -> Self {
         let (lo, carry) = self.lo().overflowing_add(other.lo());
         let hi = self.hi().wrapping_add(other.hi());
@@ -22,7 +22,7 @@ impl UAddSub for u128 {}
 
 trait AddSub: Int
 where
-    <Self as Int>::UnsignedInt: UAddSub,
+    <Self as MinInt>::UnsignedInt: UAddSub,
 {
     fn add(self, other: Self) -> Self {
         Self::from_unsigned(self.unsigned().uadd(other.unsigned()))
@@ -37,7 +37,7 @@ impl AddSub for i128 {}
 
 trait Addo: AddSub
 where
-    <Self as Int>::UnsignedInt: UAddSub,
+    <Self as MinInt>::UnsignedInt: UAddSub,
 {
     fn addo(self, other: Self) -> (Self, bool) {
         let sum = AddSub::add(self, other);
@@ -50,7 +50,7 @@ impl Addo for u128 {}
 
 trait Subo: AddSub
 where
-    <Self as Int>::UnsignedInt: UAddSub,
+    <Self as MinInt>::UnsignedInt: UAddSub,
 {
     fn subo(self, other: Self) -> (Self, bool) {
         let sum = AddSub::sub(self, other);