factor: Fix for old Rust

src/uu/factor/build.rs

@@ -58,7 +58,7 @@ fn main() {
     let mut x = primes.next().unwrap();
     for next in primes {
         // format the table
-        let outstr = format!("({}, {}, {}),", x, inv_mod_u64(x), u64::MAX / x);
+        let outstr = format!("({}, {}, {}),", x, inv_mod_u64(x), std::u64::MAX / x);
         if cols + outstr.len() > MAX_WIDTH {
             write!(file, "\n    {}", outstr).unwrap();
             cols = 4 + outstr.len();

src/uu/factor/src/numeric.rs

@@ -40,12 +40,15 @@ pub(crate) trait Arithmetic: Copy + Sized {
         }
 
         // Check that r (reduced back to the usual representation) equals
-        // a^b % n, unless the latter computation overflows
+        //  a^b % n, unless the latter computation overflows
-        debug_assert!(self
+        // Temporarily commented-out, as there u64::checked_pow is not available
-            .to_u64(_a)
+        //  on the minimum supported Rust version, nor is an appropriate method
-            .checked_pow(_b as u32)
+        //  for compiling the check conditionally.
-            .map(|r| r % self.modulus() == self.to_u64(result))
+        //debug_assert!(self
-            .unwrap_or(true));
+        //    .to_u64(_a)
+        //    .checked_pow(_b as u32)
+        //    .map(|r| r % self.modulus() == self.to_u64(result))
+        //    .unwrap_or(true));
 
         result
     }
@@ -165,7 +168,7 @@ pub(crate) fn inv_mod_u64(a: u64) -> u64 {
             // special case when we're just starting out
             // This works because we know that
             // a does not divide 2^64, so floor(2^64 / a) == floor((2^64-1) / a);
-            u64::MAX
+            std::u64::MAX
         } else {
             r
         } / newr;