Put iterator code in a separate module

The amount of stuff in lib.rs has become somewhat overwhelming.

src/iter.rs

@@ -0,0 +1,114 @@
+use crate::{BitFlag, BitFlags, BitFlagNum};
+use core::iter::{FromIterator, FusedIterator};
+
+impl<T> BitFlags<T>
+where
+    T: BitFlag,
+{
+    /// Iterate over the `BitFlags`.
+    ///
+    /// ```
+    /// # use enumflags2::{bitflags, make_bitflags};
+    /// # #[bitflags]
+    /// # #[derive(Clone, Copy, PartialEq, Debug)]
+    /// # #[repr(u8)]
+    /// # enum MyFlag {
+    /// #     A = 1 << 0,
+    /// #     B = 1 << 1,
+    /// #     C = 1 << 2,
+    /// # }
+    /// let flags = make_bitflags!(MyFlag::{A | C});
+    ///
+    /// flags.iter()
+    ///     .for_each(|flag| println!("{:?}", flag));
+    /// ```
+    #[inline]
+    pub fn iter(self) -> Iter<T> {
+        Iter { rest: self }
+    }
+}
+
+impl<T: BitFlag> IntoIterator for BitFlags<T> {
+    type IntoIter = Iter<T>;
+    type Item = T;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.iter()
+    }
+}
+
+/// Iterator that yields each flag set in a `BitFlags`.
+#[derive(Clone, Debug)]
+pub struct Iter<T: BitFlag> {
+    rest: BitFlags<T>,
+}
+
+impl<T> Iterator for Iter<T>
+where
+    T: BitFlag,
+{
+    type Item = T;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.rest.is_empty() {
+            None
+        } else {
+            // SAFETY: `flag` will be a single bit, because
+            // x & -x = x & (~x + 1), and the increment causes only one 0 -> 1 transition.
+            // The invariant of `from_bits_unchecked` is satisfied, because bits & x
+            // is a subset of bits, which we know are the valid bits.
+            unsafe {
+                let bits = self.rest.bits();
+                let flag: T::Numeric = bits & bits.wrapping_neg();
+                let flag: T = core::mem::transmute_copy(&flag);
+                self.rest = BitFlags::from_bits_unchecked(bits & (bits - BitFlagNum::ONE));
+                Some(flag)
+            }
+        }
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        let l = self.rest.len();
+        (l, Some(l))
+    }
+}
+
+impl<T> ExactSizeIterator for Iter<T>
+where
+    T: BitFlag,
+{
+    fn len(&self) -> usize {
+        self.rest.len()
+    }
+}
+
+impl<T: BitFlag> FusedIterator for Iter<T> {}
+
+impl<T, B> FromIterator<B> for BitFlags<T>
+where
+    T: BitFlag,
+    B: Into<BitFlags<T>>,
+{
+    #[inline]
+    fn from_iter<I>(it: I) -> BitFlags<T>
+    where
+        I: IntoIterator<Item = B>,
+    {
+        it.into_iter()
+            .fold(BitFlags::empty(), |acc, flag| acc | flag)
+    }
+}
+
+impl<T, B> Extend<B> for BitFlags<T>
+where
+    T: BitFlag,
+    B: Into<BitFlags<T>>,
+{
+    #[inline]
+    fn extend<I>(&mut self, it: I)
+    where
+        I: IntoIterator<Item = B>,
+    {
+        *self = it.into_iter().fold(*self, |acc, flag| acc | flag)
+    }
+}

src/lib.rs

@@ -93,7 +93,6 @@
 #![cfg_attr(all(not(test), not(feature = "std")), no_std)]
 
 use core::hash::{Hash, Hasher};
-use core::iter::{FromIterator, FusedIterator};
 use core::marker::PhantomData;
 use core::{cmp, ops};
 
@@ -406,6 +405,9 @@ mod formatting;
 mod fallible;
 pub use crate::fallible::FromBitsError;
 
+mod iter;
+pub use crate::iter::Iter;
+
 /// Represents a set of flags of some type `T`.
 /// `T` must have the `#[bitflags]` attribute applied.
 ///
@@ -792,86 +794,8 @@ where
             self.remove(other);
         }
     }
-
-    /// Iterate over the `BitFlags`.
-    ///
-    /// ```
-    /// # use enumflags2::{bitflags, make_bitflags};
-    /// # #[bitflags]
-    /// # #[derive(Clone, Copy, PartialEq, Debug)]
-    /// # #[repr(u8)]
-    /// # enum MyFlag {
-    /// #     A = 1 << 0,
-    /// #     B = 1 << 1,
-    /// #     C = 1 << 2,
-    /// # }
-    /// let flags = make_bitflags!(MyFlag::{A | C});
-    ///
-    /// flags.iter()
-    ///     .for_each(|flag| println!("{:?}", flag));
-    /// ```
-    #[inline]
-    pub fn iter(self) -> Iter<T> {
-        Iter { rest: self }
-    }
-}
-
-impl<T: BitFlag> IntoIterator for BitFlags<T> {
-    type IntoIter = Iter<T>;
-    type Item = T;
-
-    fn into_iter(self) -> Self::IntoIter {
-        self.iter()
-    }
-}
-
-/// Iterator that yields each flag set in a `BitFlags`.
-#[derive(Clone, Debug)]
-pub struct Iter<T: BitFlag> {
-    rest: BitFlags<T>,
-}
-
-impl<T> Iterator for Iter<T>
-where
-    T: BitFlag,
-{
-    type Item = T;
-
-    fn next(&mut self) -> Option<Self::Item> {
-        if self.rest.is_empty() {
-            None
-        } else {
-            // SAFETY: `flag` will be a single bit, because
-            // x & -x = x & (~x + 1), and the increment causes only one 0 -> 1 transition.
-            // The invariant of `from_bits_unchecked` is satisfied, because bits & x
-            // is a subset of bits, which we know are the valid bits.
-            unsafe {
-                let bits = self.rest.bits();
-                let flag: T::Numeric = bits & bits.wrapping_neg();
-                let flag: T = core::mem::transmute_copy(&flag);
-                self.rest = BitFlags::from_bits_unchecked(bits & (bits - BitFlagNum::ONE));
-                Some(flag)
-            }
-        }
-    }
-
-    fn size_hint(&self) -> (usize, Option<usize>) {
-        let l = self.rest.len();
-        (l, Some(l))
-    }
 }
 
-impl<T> ExactSizeIterator for Iter<T>
-where
-    T: BitFlag,
-{
-    fn len(&self) -> usize {
-        self.rest.len()
-    }
-}
-
-impl<T: BitFlag> FusedIterator for Iter<T> {}
-
 for_each_uint! { $ty $hide_docs =>
     impl<T> BitFlags<T, $ty> {
         /// Create a new BitFlags unsafely, without checking if the bits form
@@ -1127,35 +1051,6 @@ where
     }
 }
 
-impl<T, B> FromIterator<B> for BitFlags<T>
-where
-    T: BitFlag,
-    B: Into<BitFlags<T>>,
-{
-    #[inline]
-    fn from_iter<I>(it: I) -> BitFlags<T>
-    where
-        I: IntoIterator<Item = B>,
-    {
-        it.into_iter()
-            .fold(BitFlags::empty(), |acc, flag| acc | flag)
-    }
-}
-
-impl<T, B> Extend<B> for BitFlags<T>
-where
-    T: BitFlag,
-    B: Into<BitFlags<T>>,
-{
-    #[inline]
-    fn extend<I>(&mut self, it: I)
-    where
-        I: IntoIterator<Item = B>,
-    {
-        *self = it.into_iter().fold(*self, |acc, flag| acc | flag)
-    }
-}
-
 #[cfg(feature = "serde")]
 mod impl_serde {
     use super::{BitFlag, BitFlags};