make OPoint call T::fmt to respect formatting modifiers

src/geometry/point.rs

@@ -511,12 +511,26 @@ where
 
         let mut it = self.coords.iter();
 
-        write!(f, "{}", *it.next().unwrap())?;
+        <T as fmt::Display>::fmt(it.next().unwrap(), f)?;
 
         for comp in it {
-            write!(f, ", {}", *comp)?;
+            write!(f, ", ")?;
+            <T as fmt::Display>::fmt(comp, f)?;
         }
 
         write!(f, "}}")
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn display_fmt_respects_modifiers() {
+        let p = crate::Point3::new(1.23, 3.45, 5.67);
+        assert_eq!(&format!("{p}"), "{1.23, 3.45, 5.67}");
+        assert_eq!(&format!("{p:.1}"), "{1.2, 3.5, 5.7}");
+        assert_eq!(&format!("{p:.0}"), "{1, 3, 6}");
+    }
+}