From 1fb03ca18aa2ef6a9cc7bb706cd0fc604fcf270c Mon Sep 17 00:00:00 2001
From: Sam Cappleman-Lynes <sam.capplemanlynes@gmail.com>
Date: Fri, 30 Jun 2017 00:39:37 +0100
Subject: [PATCH] Make new code work on rustc-1.8.0

 - Don't apply attributes to statements (1.12.0)
 - Don't use checked_abs (1.13.0)
---
 bigint/src/bigint.rs  | 17 +++++++++++------
 bigint/src/biguint.rs |  2 ++
 bigint/src/lib.rs     | 10 ++++++++++
 bigint/src/macros.rs  | 40 ++++------------------------------------
 4 files changed, 27 insertions(+), 42 deletions(-)

diff --git a/bigint/src/bigint.rs b/bigint/src/bigint.rs
index dfb69d4..ece48b2 100644
--- a/bigint/src/bigint.rs
+++ b/bigint/src/bigint.rs
@@ -28,6 +28,9 @@ use biguint;
 use biguint::to_str_radix_reversed;
 use biguint::BigUint;
 
+use UsizePromotion;
+use IsizePromotion;
+
 #[cfg(test)]
 #[path = "tests/bigint.rs"]
 mod bigint_tests;
@@ -301,17 +304,19 @@ impl Signed for BigInt {
 
 // A convenience method for getting the absolute value of an i32 in a u32.
 fn i32_abs_as_u32(a: i32) -> u32 {
-    match a.checked_abs() {
-        Some(x) => x as u32,
-        None => a as u32
+    if a == i32::min_value() {
+        a as u32
+    } else {
+        a.abs() as u32
     }
 }
 
 // A convenience method for getting the absolute value of an i64 in a u64.
 fn i64_abs_as_u64(a: i64) -> u64 {
-    match a.checked_abs() {
-        Some(x) => x as u64,
-        None => a as u64
+    if a == i64::min_value() {
+        a as u64
+    } else {
+        a.abs() as u64
     }
 }
 
diff --git a/bigint/src/biguint.rs b/bigint/src/biguint.rs
index 7af2e71..38f7f29 100644
--- a/bigint/src/biguint.rs
+++ b/bigint/src/biguint.rs
@@ -27,6 +27,8 @@ use self::algorithms::{__add2, add2, sub2, sub2rev};
 use self::algorithms::{biguint_shl, biguint_shr};
 use self::algorithms::{cmp_slice, fls, ilog2};
 
+use UsizePromotion;
+
 use ParseBigIntError;
 
 #[cfg(test)]
diff --git a/bigint/src/lib.rs b/bigint/src/lib.rs
index 586eeec..02b9992 100644
--- a/bigint/src/lib.rs
+++ b/bigint/src/lib.rs
@@ -88,6 +88,16 @@ use std::error::Error;
 use std::num::ParseIntError;
 use std::fmt;
 
+#[cfg(target_pointer_width = "32")]
+type UsizePromotion = u32;
+#[cfg(target_pointer_width = "64")]
+type UsizePromotion = u64;
+
+#[cfg(target_pointer_width = "32")]
+type IsizePromotion = i32;
+#[cfg(target_pointer_width = "64")]
+type IsizePromotion = i64;
+
 #[derive(Debug, PartialEq)]
 pub enum ParseBigIntError {
     ParseInt(ParseIntError),
diff --git a/bigint/src/macros.rs b/bigint/src/macros.rs
index a8143ad..7705f55 100644
--- a/bigint/src/macros.rs
+++ b/bigint/src/macros.rs
@@ -210,35 +210,17 @@ macro_rules! promote_scalars {
     }
 }
 
-macro_rules! promote_unsigned_scalars_to_u32 {
+macro_rules! promote_unsigned_scalars {
     (impl $imp:ident for $res:ty, $method:ident) => {
-        #[cfg(target_pointer_width = "32")]
-        promote_scalars!(impl $imp<u32> for $res, $method, u8, u16, usize);
-        #[cfg(target_pointer_width = "64")]
         promote_scalars!(impl $imp<u32> for $res, $method, u8, u16);
+        promote_scalars!(impl $imp<UsizePromotion> for $res, $method, usize);
     }
 }
 
-macro_rules! promote_unsigned_scalars_to_u64 {
+macro_rules! promote_signed_scalars {
     (impl $imp:ident for $res:ty, $method:ident) => {
-        #[cfg(target_pointer_width = "64")]
-        promote_scalars!(impl $imp<u64> for $res, $method, usize);
-    }
-}
-
-macro_rules! promote_signed_scalars_to_i32 {
-    (impl $imp:ident for $res:ty, $method:ident) => {
-        #[cfg(target_pointer_width = "32")]
-        promote_scalars!(impl $imp<i32> for $res, $method, i8, i16, isize);
-        #[cfg(target_pointer_width = "64")]
         promote_scalars!(impl $imp<i32> for $res, $method, i8, i16);
-    }
-}
-
-macro_rules! promote_signed_scalars_to_i64 {
-    (impl $imp:ident for $res:ty, $method:ident) => {
-        #[cfg(target_pointer_width = "64")]
-        promote_scalars!(impl $imp<i64> for $res, $method, isize);
+        promote_scalars!(impl $imp<IsizePromotion> for $res, $method, isize);
     }
 }
 
@@ -284,20 +266,6 @@ macro_rules! forward_all_scalar_binop_to_val_val_commutative {
     }
 }
 
-macro_rules! promote_unsigned_scalars {
-    (impl $imp:ident for $res:ty, $method:ident) => {
-        promote_unsigned_scalars_to_u32!(impl $imp for $res, $method);
-        promote_unsigned_scalars_to_u64!(impl $imp for $res, $method);
-    }
-}
-
-macro_rules! promote_signed_scalars {
-    (impl $imp:ident for $res:ty, $method:ident) => {
-        promote_signed_scalars_to_i32!(impl $imp for $res, $method);
-        promote_signed_scalars_to_i64!(impl $imp for $res, $method);
-    }
-}
-
 macro_rules! promote_all_scalars {
     (impl $imp:ident for $res:ty, $method:ident) => {
         promote_unsigned_scalars!(impl $imp for $res, $method);