Provide rem_euclid in FloatFuncs

Author: tomcur

src/common.rs

@@ -34,6 +34,9 @@ macro_rules! define_float_funcs {
             /// Special implementation for signum, because libm doesn't have it.
             fn signum(self) -> Self;
 
+            /// Special implementation for `rem_euclid`, because libm doesn't have it.
+            fn rem_euclid(self, rhs: Self) -> Self;
+
             $(fn $name(self $(,$arg: $arg_ty)*) -> $ret;)+
         }
 
@@ -51,6 +54,16 @@ macro_rules! define_float_funcs {
                 }
             }
 
+            #[inline]
+            fn rem_euclid(self, rhs: f32) -> f32 {
+                let r = self % rhs;
+                if r < 0.0 {
+                    r + rhs.abs()
+                } else {
+                    r
+                }
+            }
+
             $(fn $name(self $(,$arg: $arg_ty)*) -> $ret {
                 #[cfg(feature = "libm")]
                 return libm::$lfname(self $(,$arg as _)*);
@@ -73,6 +86,16 @@ macro_rules! define_float_funcs {
                 }
             }
 
+            #[inline]
+            fn rem_euclid(self, rhs: f64) -> f64 {
+                let r = self % rhs;
+                if r < 0.0 {
+                    r + rhs.abs()
+                } else {
+                    r
+                }
+            }
+
             $(fn $name(self $(,$arg: $arg_ty)*) -> $ret {
                 #[cfg(feature = "libm")]
                 return libm::$lname(self $(,$arg as _)*);