incr: added type dispatch

Cargo.toml

@@ -18,8 +18,9 @@ categories = ["embedded", "no-std", "data-structures"]
 [dependencies]
 
 [features]
-default = []
+default = ["const-generics"]
 # This is a no-op feature only provided for compatibility in case it is
 # explicitly selected by a user. This crate works without explicit indication
 # both on std and no_std systems.
 std = []
+const-generics = []

src/lib.rs

@@ -31,6 +31,61 @@ use lib::core::cmp::{Ord, Ordering, PartialOrd};
 
 use lib::core::fmt::{Binary, Display, Formatter, LowerHex, Octal, UpperHex};
 
+#[cfg(feature = "const-generics")]
+pub trait ToUnsignedType {
+    type Output;
+}
+
+#[cfg(feature = "const-generics")]
+pub trait ToSignedType {
+    type Output;
+}
+
+#[cfg(feature = "const-generics")]
+pub struct Const<const N: usize>;
+
+#[cfg(feature = "const-generics")]
+pub type Unsigned<const N: usize> = <Const<N> as ToUnsignedType>::Output;
+
+#[cfg(feature = "const-generics")]
+pub type Signed<const N: usize> = <Const<N> as ToSignedType>::Output;
+
+#[cfg(feature = "const-generics")]
+macro_rules! impl_type_dispatch {
+    (signed, $name:ident, $bits:expr) => {
+        impl ToSignedType for Const<$bits> {
+            type Output = $name;
+        }
+    };
+    (unsigned, $name:ident, $bits:expr) => {
+        impl ToUnsignedType for Const<$bits> {
+            type Output = $name;
+        }
+    };
+}
+
+#[cfg(feature = "const-generics")]
+impl_type_dispatch!(signed, i8, 8);
+#[cfg(feature = "const-generics")]
+impl_type_dispatch!(signed, i16, 16);
+#[cfg(feature = "const-generics")]
+impl_type_dispatch!(signed, i32, 32);
+#[cfg(feature = "const-generics")]
+impl_type_dispatch!(signed, i64, 64);
+#[cfg(feature = "const-generics")]
+impl_type_dispatch!(signed, i128, 128);
+
+#[cfg(feature = "const-generics")]
+impl_type_dispatch!(unsigned, u8, 8);
+#[cfg(feature = "const-generics")]
+impl_type_dispatch!(unsigned, u16, 16);
+#[cfg(feature = "const-generics")]
+impl_type_dispatch!(unsigned, u32, 32);
+#[cfg(feature = "const-generics")]
+impl_type_dispatch!(unsigned, u64, 64);
+#[cfg(feature = "const-generics")]
+impl_type_dispatch!(unsigned, u128, 128);
+
 macro_rules! define_unsigned {
     ($name:ident, $bits:expr, $type:ident) => {define_unsigned!(#[doc=""], $name, $bits, $type);};
     (#[$doc:meta], $name:ident, $bits:expr, $type:ident) => {
@@ -51,6 +106,9 @@ macro_rules! define_unsigned {
 
         implement_common!($name, $bits, $type);
 
+        #[cfg(feature = "const-generics")]
+        impl_type_dispatch!(unsigned, $name, $bits);
+
     }
 }
 
@@ -79,6 +137,9 @@ macro_rules! define_signed {
 
         implement_common!($name, $bits, $type);
 
+        #[cfg(feature = "const-generics")]
+        impl_type_dispatch!(signed, $name, $bits);
+
     }
 }