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+# What `#[derive(Constructor)]` generates
+
+A common pattern in Rust is to create a static constructor method called
+`new`. This method is can then be used to create an instance of a struct. You
+can now derive this method by using `#[derive(Constructor)]`, even though
+`Constructor` it is not an actual trait. The generated `new` method is very
+similar to the `from` method when deriving `From`, except that it takes multiple
+arguments instead of a tuple.
+
+
+
+
+## Tuple structs
+
+When deriving `Constructor` for a tuple struct with a two fields like this:
+
+```rust
+# use derive_more::Constructor;
+#
+#[derive(Constructor)]
+struct MyInts(i32, i32);
+```
+
+Code like this will be generated:
+
+```rust
+# struct MyInts(i32, i32);
+impl MyInts {
+    pub const fn new(__0: i32, __1: i32) -> MyInts {
+        MyInts(__0, __1)
+    }
+}
+```
+
+The generated code is similar for more or less fields.
+
+
+
+
+## Regular structs
+
+For regular structs almost the same code is generated as for tuple structs
+except that it assigns the fields differently.
+
+```rust
+# use derive_more::Constructor;
+#
+#[derive(Constructor)]
+struct Point2D {
+    x: i32,
+    y: i32,
+}
+```
+
+Code like this will be generated:
+
+```rust
+# struct Point2D {
+#     x: i32,
+#     y: i32,
+# }
+impl Point2D {
+    pub const fn new(x: i32, y: i32) -> Point2D {
+        Point2D { x: x, y: y }
+    }
+}
+```
+
+The generated code is similar for more or less fields.
+
+
+
+
+## Enums
+
+Currently `Constructor` cannot be derived for enums. This is because the `new`
+method might then need to have a different number of arguments. This is
+currently not supported by Rust. So this functionality will not be added until
+this [RFC](https://github.com/rust-lang/rfcs/issues/376) (or a similar one) is
+accepted and implemented.