Fix compile errors

src/lib.rs

@@ -40,10 +40,8 @@ impl Display for TryNewError {
 }
 
 #[cfg_attr(feature = "const_convert_and_const_trait_impl", const_trait)]
-pub trait Number: Sized {
-    type UnderlyingType: Copy
-        + Clone
-        + Number
+pub trait Number: Sized + Copy + Clone {
+    type UnderlyingType: Number
         + Debug
         + From<u8>
         + TryFrom<u16>
@@ -68,8 +66,16 @@ pub trait Number: Sized {
 
     fn value(self) -> Self::UnderlyingType;
 
+    #[cfg(feature = "const_convert_and_const_trait_impl")]
+    fn new_<T: ~const Number>(value: T) -> Self;
+    #[cfg(not(feature = "const_convert_and_const_trait_impl"))]
     fn new_<T: Number>(value: T) -> Self;
 
+    /// Creates an instance from the given `value`. Unlike the various `new...` functions, this
+    /// will never fail as the value is masked to the result size.
+    #[cfg(feature = "const_convert_and_const_trait_impl")]
+    fn masked_new<T: ~const Number>(value: T) -> Self;
+    #[cfg(not(feature = "const_convert_and_const_trait_impl"))]
     fn masked_new<T: Number>(value: T) -> Self;
 
     fn as_u8(&self) -> u8;
@@ -82,6 +88,13 @@ pub trait Number: Sized {
 
     fn as_u128(&self) -> u128;
 
+    #[cfg(feature = "const_convert_and_const_trait_impl")]
+    #[inline]
+    fn as_<T: ~const Number>(self) -> T {
+        T::masked_new(self)
+    }
+
+    #[cfg(not(feature = "const_convert_and_const_trait_impl"))]
     #[inline]
     fn as_<T: Number>(self) -> T {
         T::masked_new(self)
@@ -108,7 +121,7 @@ macro_rules! impl_number_native {
                 fn value(self) -> Self::UnderlyingType { self }
 
                 #[inline]
-                fn new_<T: Number>(value: T) -> Self {
+                fn new_<T: ~const Number>(value: T) -> Self {
                     match Self::BITS {
                         8 => value.as_u8() as Self,
                         16 => value.as_u16() as Self,
@@ -120,7 +133,7 @@ macro_rules! impl_number_native {
                 }
 
                 #[inline]
-                fn masked_new<T: Number>(value: T) -> Self {
+                fn masked_new<T: ~const Number>(value: T) -> Self {
                     // Primitive types don't need masking
                     Self::new_(value)
                 }