1 files changed, 47 insertions, 0 deletions
diff --git a/src/internal.rs b/src/internal.rs
new file mode 100644
index 0000000..166e25f
--- /dev/null
+++ b/src/internal.rs
@@ -0,0 +1,47 @@
+use std::fmt;
+use std::ops::{Add, Sub, AddAssign, SubAssign, Mul, MulAssign, Div, DivAssign};
+
+pub trait Internal:
+    Copy + Clone + PartialEq + fmt::Debug + fmt::Display + PartialOrd +
+    Add<Output=Self> + Sub<Output=Self> + AddAssign + SubAssign +
+    Mul<Output=Self> + MulAssign + Div<Output=Self> + DivAssign +
+{
+    const ZERO: Self;
+
+    fn as_usize(&self) -> usize;
+
+    fn as_f64(&self) -> f64;
+}
+
+macro_rules! impl_for_type {
+    ($z:expr, $t:ty) => {
+        impl Internal for $t {
+            const ZERO: Self = $z;
+
+            fn as_usize(&self) -> usize {
+                *self as usize
+            }
+
+            fn as_f64(&self) -> f64 {
+                *self as f64
+            }
+        }
+    };
+}
+
+impl_for_type!(0, u8);
+impl_for_type!(0, u16);
+impl_for_type!(0, u32);
+impl_for_type!(0, u64);
+impl_for_type!(0, u128);
+impl_for_type!(0, usize);
+
+impl_for_type!(0, i8);
+impl_for_type!(0, i16);
+impl_for_type!(0, i32);
+impl_for_type!(0, i64);
+impl_for_type!(0, i128);
+impl_for_type!(0, isize);
+
+impl_for_type!(0.0, f32);
+impl_for_type!(0.0, f64);