Initial commit!

src/unsigned/conversion.rs

@@ -0,0 +1,83 @@
+macro_rules! generate_base_conversions
+{
+    ($name: ident) => {
+        generate_base_type_convert!($name, u8);
+        generate_base_type_convert!($name, u16);
+        generate_base_type_convert!($name, u32);
+        generate_base_type_convert!($name, u64);
+        generate_base_type_convert!($name, usize);
+
+        impl From<u128> for $name {
+            fn from(x: u128) -> $name {
+                let mut res = $name::zero();
+                res.value[0] = x as u64;
+                res.value[1] = (x >> 64) as u64;
+                res
+            }
+        }
+    };
+    () => {};
+}
+
+macro_rules! conversion_impls
+{
+    ($name: ident, $other: ident) => {
+        impl<'a> From<&'a $other> for $name {
+            fn from(x: &$other) -> $name {
+                let mut res = $name::zero();
+                let     len = res.value.len();
+                assert!(x.value.len() > res.value.len());
+                res.value.copy_from_slice(&x.value[0..len]);
+                res
+            }
+        }
+
+        impl<'a> From<&'a $name> for $other {
+            fn from(x: &$name) -> $other {
+                let mut res = $other::zero();
+                let     len = x.value.len();
+
+                assert!(x.value.len() < res.value.len());
+                res.value[0..len].copy_from_slice(&x.value);
+                res
+            }
+        }
+
+        impl From<$other> for $name {
+            fn from(x: $other) -> $name {
+                $name::from(&x)
+            }
+        }
+
+        impl From<$name> for $other {
+            fn from(x: $name) -> $other {
+                $other::from(&x)
+            }
+        }
+    };
+}
+
+macro_rules! generate_base_type_convert
+{
+    ($name: ident, $base: ident) => {
+        impl From<$base> for $name {
+            fn from(x: $base) -> $name {
+                let mut res = $name::zero();
+                res.value[0] = x as u64;
+                res
+            }
+        }
+
+        impl From<$name> for $base {
+            fn from(x: $name) -> $base {
+                x.value[0] as $base
+            }
+        }
+
+        impl<'a> From<&'a $name> for $base {
+            fn from(x: &$name) -> $base {
+                x.value[0] as $base
+            }
+        }
+    }
+}