Merge pull request #19 from yvt/master

Replace unsafe transmutes with to_bits and from_bits
mikedilger · Jul 18, 2019 · 3e605bd · 3e605bd
2 parents 236fb25 + 708c66a
commit 3e605bd
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Showing 2 changed files with 14 additions and 14 deletions.
diff --git a/src/ulps.rs b/src/ulps.rs
@@ -47,12 +47,12 @@ impl Ulps for f32 {
         // IEEE754 defined floating point storage representation to
         // maintain their order when their bit patterns are interpreted as
         // integers.  This is a huge boon to the task at hand, as we can
-        // (unsafely) cast to integers to find out how many ULPs apart any
+        // reinterpret them as integers to find out how many ULPs apart any
         // two floats are
 
         // Setup integer representations of the input
-        let ai32: i32 = unsafe { mem::transmute::<f32,i32>(*self) };
-        let bi32: i32 = unsafe { mem::transmute::<f32,i32>(*other) };
+        let ai32: i32 = self.to_bits() as i32;
+        let bi32: i32 = other.to_bits() as i32;
 
         ai32.wrapping_sub(bi32)
     }
@@ -124,8 +124,8 @@ fn f32_ulps_test4() {
 #[test]
 fn f32_ulps_test5() {
     let x: f32 = 2.0;
-    let ulps: i32 = unsafe { mem::transmute(x) };
-    let x2: f32 = unsafe { mem::transmute(ulps) };
+    let ulps: i32 = x.to_bits() as i32;
+    let x2: f32 = <f32>::from_bits(ulps as u32);
     assert_eq!(x, x2);
 }
 
@@ -147,12 +147,12 @@ impl Ulps for f64 {
         // IEEE754 defined floating point storage representation to
         // maintain their order when their bit patterns are interpreted as
         // integers.  This is a huge boon to the task at hand, as we can
-        // (unsafely) cast to integers to find out how many ULPs apart any
+        // reinterpret them as integers to find out how many ULPs apart any
         // two floats are
 
         // Setup integer representations of the input
-        let ai64: i64 = unsafe { mem::transmute::<f64,i64>(*self) };
-        let bi64: i64 = unsafe { mem::transmute::<f64,i64>(*other) };
+        let ai64: i64 = self.to_bits() as i64;
+        let bi64: i64 = other.to_bits() as i64;
 
         ai64.wrapping_sub(bi64)
     }
@@ -224,8 +224,8 @@ fn f64_ulps_test4() {
 #[test]
 fn f64_ulps_test5() {
     let x: f64 = 2.0;
-    let ulps: i64 = unsafe { mem::transmute(x) };
-    let x2: f64 = unsafe { mem::transmute(ulps) };
+    let ulps: i64 = x.to_bits() as i64;
+    let x2: f64 = <f64>::from_bits(ulps as u64);
     assert_eq!(x, x2);
 }
 

diff --git a/src/ulps_ord.rs b/src/ulps_ord.rs
@@ -174,8 +174,8 @@ fn f32_approx_cmp_vs_partial_cmp() {
     let mut yf: f32;
     for xbits in testcases.iter() {
         for ybits in testcases.iter() {
-            xf = unsafe { mem::transmute::<u32,f32>(*xbits) };
-            yf = unsafe { mem::transmute::<u32,f32>(*ybits) };
+            xf = <f32>::from_bits(*xbits);
+            yf = <f32>::from_bits(*ybits);
             if let Some(ordering) = xf.partial_cmp(&yf) {
                 if ordering != xf.approx_cmp_ulps(&yf, 0) {
                     panic!("{} ({:x}) vs {} ({:x}): partial_cmp gives {:?} \
@@ -288,8 +288,8 @@ fn f64_approx_cmp_ulps_vs_partial_cmp() {
     let mut yf: f64;
     for xbits in testcases.iter() {
         for ybits in testcases.iter() {
-            xf = unsafe { mem::transmute::<u64,f64>(*xbits) };
-            yf = unsafe { mem::transmute::<u64,f64>(*ybits) };
+            xf = <f64>::from_bits(*xbits);
+            yf = <f64>::from_bits(*ybits);
             if let Some(ordering) = xf.partial_cmp(&yf) {
                 if ordering != xf.approx_cmp_ulps(&yf, 0) {
                     panic!("{} ({:x}) vs {} ({:x}): partial_cmp gives {:?} \