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+# Using `#[derive(Deref)]`
+
+Deriving `Deref` only works for a single field of a struct.
+It's possible to use it in two ways:
+
+1. Dereferencing to the field, i.e. like if your type was a reference type.
+2. Doing a dereference on the field, for when the field itself is a reference type like `&` and `Box`.
+
+With `#[deref]` or `#[deref(ignore)]` it's possible to indicate the field that
+you want to derive `Deref` for.
+
+
+
+
+## Example usage
+
+```rust
+# use derive_more::Deref;
+#
+#[derive(Deref)]
+struct Num {
+    num: i32,
+}
+
+#[derive(Deref)]
+#[deref(forward)]
+struct MyBoxedInt(Box<i32>);
+
+// You can specify the field you want to derive `Deref` for.
+#[derive(Deref)]
+struct CoolVec {
+    cool: bool,
+    #[deref]
+    vec: Vec<i32>,
+}
+
+let num = Num{num: 123};
+let boxed = MyBoxedInt(Box::new(123));
+let cool_vec = CoolVec{cool: true, vec: vec![123]};
+assert_eq!(123, *num);
+assert_eq!(123, *boxed);
+assert_eq!(vec![123], *cool_vec);
+```
+
+
+
+
+## Structs
+
+When deriving a non-forwarded `Deref` for a struct:
+
+```rust
+# use derive_more::Deref;
+#
+#[derive(Deref)]
+struct CoolVec {
+    cool: bool,
+    #[deref]
+    vec: Vec<i32>,
+}
+```
+
+Code like this will be generated:
+
+```rust
+# struct CoolVec {
+#     cool: bool,
+#     vec: Vec<i32>,
+# }
+impl ::core::ops::Deref for CoolVec {
+    type Target = Vec<i32>;
+    #[inline]
+    fn deref(&self) -> &Self::Target {
+        &self.vec
+    }
+}
+```
+
+When deriving a forwarded `Deref` for a struct:
+
+```rust
+# use derive_more::Deref;
+#
+#[derive(Deref)]
+#[deref(forward)]
+struct MyBoxedInt(Box<i32>);
+```
+
+Code like this will be generated:
+
+```rust
+# struct MyBoxedInt(Box<i32>);
+impl ::core::ops::Deref for MyBoxedInt {
+    type Target = <Box<i32> as ::core::ops::Deref>::Target;
+    #[inline]
+    fn deref(&self) -> &Self::Target {
+        <Box<i32> as ::core::ops::Deref>::deref(&self.0)
+    }
+}
+```
+
+
+
+
+## Enums
+
+Deriving `Deref` is not supported for enums.