fractional-scale: implement accurate rounding

src/utils/array_to_tuple.rs

@@ -0,0 +1,28 @@
+pub trait ArrayToTuple {
+    type Tuple;
+
+    fn to_tuple(self) -> Self::Tuple;
+}
+
+macro_rules! ignore {
+    ($t:tt) => {
+        T
+    };
+}
+
+macro_rules! array_to_tuple {
+    ($n:expr, $($field:ident,)*) => {
+        impl<T> ArrayToTuple for [T; $n] {
+            type Tuple = ($(ignore!($field),)*);
+
+            fn to_tuple(self) -> Self::Tuple {
+                let [$($field,)*] = self;
+                #[allow(clippy::allow_attributes)]
+                #[allow(clippy::unused_unit)]
+                ($($field,)*)
+            }
+        }
+    };
+}
+
+array_to_tuple!(2, t1, t2,);