fix u128 for older Rust

Author: mohrezaei

src/power10.rs

@@ -30,18 +30,28 @@ static POWER10_HASH_U64: [u64;32] = [1, 100000000000, 10000000000000000, 0, 1000
     0, 1000, 0, 0, 0, 1000000000000, 0, 1000000000000000, 0, 100000000000000,
     1000000000000000000, 100, 100000000, 100000000000000000, 0, 10000000000000000000,
     10000, 100000, 0, 1000000000, 0, 10000000000, 0];
+
 #[cfg(has_i128)]
-static POWER10_HASH_U128: [u128;64] = [100000000000000000000000000000000000, 0, 100000000000000000000000000000000,
-    0, 1000, 0, 0, 0, 0,
-    1000000000000000000000000000000000000, 1000000000, 0, 100000000000000, 100, 0, 0, 0, 100000, 0, 0,
-    10000000000000, 100000000000, 10000000000000000000, 0, 0, 10000000000000000000000000000000000,
-    100000000, 0, 1000000000000000000000000000000000, 1000000000000, 0, 100000000000000000000000000000000000000,
-    10000000000000000, 100000000000000000000000000, 0, 10000000000000000000000000000000000000,
-    1000000000000000000, 1, 10000000000000000000000000, 1000000000000000000000000, 100000000000000000000000000000,
-    10000000, 10000000000000000000000000000, 0, 1000000000000000000000000000, 100000000000000000, 10000,
-    0, 1000000, 1000000000000000000000000000000, 0, 100000000000000000000, 10, 0, 10000000000,
-    10000000000000000000000, 0, 0, 10000000000000000000000000000000, 1000000000000000000000, 0,
-    100000000000000000000000, 1000000000000000, 0];
+mod pow10_u128 {
+    static POWER10_HASH_U128: [u128; 64] = [100000000000000000000000000000000000, 0, 100000000000000000000000000000000,
+        0, 1000, 0, 0, 0, 0,
+        1000000000000000000000000000000000000, 1000000000, 0, 100000000000000, 100, 0, 0, 0, 100000, 0, 0,
+        10000000000000, 100000000000, 10000000000000000000, 0, 0, 10000000000000000000000000000000000,
+        100000000, 0, 1000000000000000000000000000000000, 1000000000000, 0, 100000000000000000000000000000000000000,
+        10000000000000000, 100000000000000000000000000, 0, 10000000000000000000000000000000000000,
+        1000000000000000000, 1, 10000000000000000000000000, 1000000000000000000000000, 100000000000000000000000000000,
+        10000000, 10000000000000000000000000000, 0, 1000000000000000000000000000, 100000000000000000, 10000,
+        0, 1000000, 1000000000000000000000000000000, 0, 100000000000000000000, 10, 0, 10000000000,
+        10000000000000000000000, 0, 0, 10000000000000000000000000000000, 1000000000000000000000, 0,
+        100000000000000000000000, 1000000000000000, 0];
+
+    #[inline]
+    pub fn is_pow10_u128(v: u128) -> bool {
+        let mut hash: u32 = v as u32 | (((v as u64) >> 32) as u32);
+        hash = hash.wrapping_mul(1249991743).rotate_right(25);
+        v == POWER10_HASH_U128[(hash & 63) as usize]
+    }
+}
 
 // implementation note: reverse search is a bit faster than hash lookup for u8
 #[inline]
@@ -76,9 +86,7 @@ fn is_pow10_u64(v: u64) -> bool {
 #[cfg(has_i128)]
 #[inline]
 fn is_pow10_u128(v: u128) -> bool {
-    let mut hash: u32 = v as u32 | (((v as u64) >> 32) as u32);
-    hash = hash.wrapping_mul(1249991743).rotate_right(25);
-    v == POWER10_HASH_U128[(hash & 63) as usize]
+    pow10_u128::is_pow10_u128(v)
 }
 
 #[cfg(target_pointer_width = "64")]