Adds the const_generics feature

Author: c410-f3r

src/into_iter.rs

@@ -3,28 +3,39 @@ use crate::Array;
 use crate::SmallVec;
 use core::ptr;
 
+macro_rules! create_with_parts {
+(
+    <$($({$s_impl_ty_prefix:ident})? $s_impl_ty:ident$(: $s_impl_ty_bound:ident)?),*>,
+    <$s_decl_ty:ident$(, {$s_decl_const_ty:ident})?>,
+    $array_item:ty
+) => {
+
 /// An iterator that consumes a `SmallVec` and yields its items by value.
 ///
 /// Returned from [`SmallVec::into_iter`][1].
 ///
 /// [1]: struct.SmallVec.html#method.into_iter
-pub struct IntoIter<A: Array> {
-    pub(crate) data: SmallVec<A>,
+pub struct IntoIter<$($($s_impl_ty_prefix)? $s_impl_ty$(: $s_impl_ty_bound)?),*> {
+    pub(crate) data: SmallVec<$s_decl_ty$(, {$s_decl_const_ty})?>,
     pub(crate) current: usize,
     pub(crate) end: usize,
 }
 
-impl<A: Array> Drop for IntoIter<A> {
+impl<$($($s_impl_ty_prefix)? $s_impl_ty$(: $s_impl_ty_bound)?),*> Drop
+    for IntoIter<$s_decl_ty$(, {$s_decl_const_ty})?>
+{
     fn drop(&mut self) {
         for _ in self {}
     }
 }
 
-impl<A: Array> Iterator for IntoIter<A> {
-    type Item = A::Item;
+impl<$($($s_impl_ty_prefix)? $s_impl_ty$(: $s_impl_ty_bound)?),*> Iterator
+    for IntoIter<$s_decl_ty$(, {$s_decl_const_ty})?>
+{
+    type Item = $array_item;
 
     #[inline]
-    fn next(&mut self) -> Option<A::Item> {
+    fn next(&mut self) -> Option<$array_item> {
         if self.current == self.end {
             None
         } else {
@@ -43,9 +54,11 @@ impl<A: Array> Iterator for IntoIter<A> {
     }
 }
 
-impl<A: Array> DoubleEndedIterator for IntoIter<A> {
+impl<$($($s_impl_ty_prefix)? $s_impl_ty$(: $s_impl_ty_bound)?),*> DoubleEndedIterator
+    for IntoIter<$s_decl_ty$(, {$s_decl_const_ty})?>
+{
     #[inline]
-    fn next_back(&mut self) -> Option<A::Item> {
+    fn next_back(&mut self) -> Option<$array_item> {
         if self.current == self.end {
             None
         } else {
@@ -57,4 +70,13 @@ impl<A: Array> DoubleEndedIterator for IntoIter<A> {
     }
 }
 
-impl<A: Array> ExactSizeIterator for IntoIter<A> {}
+impl<$($($s_impl_ty_prefix)? $s_impl_ty$(: $s_impl_ty_bound)?),*> ExactSizeIterator
+    for IntoIter<$s_decl_ty$(, {$s_decl_const_ty})?> {}
+
+    }
+}
+
+#[cfg(feature = "const_generics")]
+create_with_parts!(<T, {const} N: usize>, <T, {N}>, T);
+#[cfg(not(feature = "const_generics"))]
+create_with_parts!(<A: Array>, <A>, A::Item);