Use void for the unreachable serializers

1 files changed, 122 insertions, 0 deletions

diff --git a/src/ser/void.rs b/src/ser/void.rs
new file mode 100644
index 0000000..4765bb7
--- /dev/null
+++ b/src/ser/void.rs
@@ -0,0 +1,122 @@
+use ser::Error;
+use serde::ser;
+use std::marker::PhantomData;
+use void;
+
+pub struct VoidSerializer<Ok> {
+    void: void::Void,
+    _marker: PhantomData<Ok>,
+}
+
+impl<Ok> ser::SerializeSeq for VoidSerializer<Ok> {
+    type Ok = Ok;
+    type Error = Error;
+
+    fn serialize_element<T: ?Sized + ser::Serialize>(&mut self,
+                                                     _value: &T)
+                                                     -> Result<(), Error> {
+        void::unreachable(self.void)
+    }
+
+    fn end(self) -> Result<Ok, Error> {
+        void::unreachable(self.void)
+    }
+}
+
+impl<Ok> ser::SerializeTuple for VoidSerializer<Ok> {
+    type Ok = Ok;
+    type Error = Error;
+
+    fn serialize_element<T: ?Sized + ser::Serialize>(&mut self,
+                                                     _value: &T)
+                                                     -> Result<(), Error> {
+        void::unreachable(self.void)
+    }
+
+    fn end(self) -> Result<Ok, Error> {
+        void::unreachable(self.void)
+    }
+}
+
+impl<Ok> ser::SerializeTupleStruct for VoidSerializer<Ok> {
+    type Ok = Ok;
+    type Error = Error;
+
+    fn serialize_field<T: ?Sized + ser::Serialize>(&mut self,
+                                                   _value: &T)
+                                                   -> Result<(), Error> {
+        void::unreachable(self.void)
+    }
+
+    fn end(self) -> Result<Ok, Error> {
+        void::unreachable(self.void)
+    }
+}
+
+impl<Ok> ser::SerializeTupleVariant for VoidSerializer<Ok> {
+    type Ok = Ok;
+    type Error = Error;
+
+    fn serialize_field<T: ?Sized + ser::Serialize>(&mut self,
+                                                   _value: &T)
+                                                   -> Result<(), Error> {
+        void::unreachable(self.void)
+    }
+
+    fn end(self) -> Result<Ok, Error> {
+        void::unreachable(self.void)
+    }
+}
+
+impl<Ok> ser::SerializeMap for VoidSerializer<Ok> {
+    type Ok = Ok;
+    type Error = Error;
+
+    fn serialize_key<T: ?Sized + ser::Serialize>(&mut self,
+                                                 _key: &T)
+                                                 -> Result<(), Error> {
+        void::unreachable(self.void)
+    }
+
+    fn serialize_value<T: ?Sized + ser::Serialize>(&mut self,
+                                                   _value: &T)
+                                                   -> Result<(), Error> {
+        void::unreachable(self.void)
+    }
+
+    fn end(self) -> Result<Ok, Error> {
+        void::unreachable(self.void)
+    }
+}
+
+impl<Ok> ser::SerializeStruct for VoidSerializer<Ok> {
+    type Ok = Ok;
+    type Error = Error;
+
+    fn serialize_field<T: ?Sized + ser::Serialize>(&mut self,
+                                                   _key: &'static str,
+                                                   _value: &T)
+                                                   -> Result<(), Error> {
+        void::unreachable(self.void)
+    }
+
+    fn end(self) -> Result<Ok, Error> {
+        void::unreachable(self.void)
+    }
+}
+
+impl<Ok> ser::SerializeStructVariant for VoidSerializer<Ok> {
+    type Ok = Ok;
+    type Error = Error;
+
+    fn serialize_field<T: ?Sized + ser::Serialize>(&mut self,
+                                                   _key: &'static str,
+                                                   _value: &T)
+                                                   -> Result<(), Error> {
+        void::unreachable(self.void)
+    }
+
+    fn end(self) -> Result<Ok, Error> {
+        void::unreachable(self.void)
+    }
+}