FIX 1 << 56 on 32-bit platforms

Author: bluss

src/error.rs

@@ -513,7 +513,7 @@ fn test_encode_decode_format() {
 
 #[test]
 fn test_encode_decode() {
-    for &i in [0, 1, 2, 3, 10, 32, 256, 1736, 16300, (1 << 56) - 1].iter() {
+    for &i in [0, 1, 2, 3, 10, 32, 256, 1736, 16300].iter() {
         let err = ShapeError::invalid_axis(i, 0);
         assert_eq!(err.info_expected_index(), Some(i));
         let err = ShapeError::invalid_axis(0, i);
@@ -525,7 +525,12 @@ fn test_encode_decode() {
     assert_eq!(err.info_actual_index(), Some((1 << 24) + 1));
 
     if size_of::<usize>() > 4 {
-        let err = ShapeError::invalid_axis(1 << 56, 1 << 56);
+        // use .wrapping_shl(_) for portability
+        let err = ShapeError::invalid_axis(1usize.wrapping_shl(56) - 1, 0);
+        assert_eq!(err.info_expected_index(), Some(1usize.wrapping_shl(56) - 1));
+        assert_eq!(err.info_actual_index(), Some(0));
+
+        let err = ShapeError::invalid_axis(1usize.wrapping_shl(56), 1usize.wrapping_shl(56));
         assert_eq!(err.info_expected_index(), None);
         assert_eq!(err.info_actual_index(), None);