fix awkward macro implementaiton

src/sys/macros.rs

@@ -175,7 +175,7 @@ macro_rules! impl_f64_newtypes {
     // NOTE: this macro def'n is awkward
     // because we sometimes need a token as
     // a type and other times as an expression
-    ($type: ty, $type_as_expr: expr) => {
+    ($type: ident) => {
         impl std::fmt::Display for $type {
             fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
                 write!(f, "{}", self.0)
@@ -280,7 +280,7 @@ macro_rules! impl_f64_newtypes {
             type Output = $type;
 
             fn add(self, rhs: Self) -> Self::Output {
-                $type_as_expr(self.0 + rhs.0)
+                $type(self.0 + rhs.0)
             }
         }
 

src/sys/newtypes.rs

@@ -179,9 +179,9 @@ pub struct Position(f64);
 #[derive(Copy, Clone, Debug, PartialEq, PartialOrd)]
 pub struct Location(f64);
 
-impl_f64_newtypes!(Time, Time);
-impl_f64_newtypes!(Position, Position);
-impl_f64_newtypes!(Location, Location);
+impl_f64_newtypes!(Time);
+impl_f64_newtypes!(Position);
+impl_f64_newtypes!(Location);
 
 // It is natural to be able to * and / times and positions
 impl_time_position_arithmetic!(Time, Position);