feat(errors): Switch Error::custom to use Into<String>

serde/src/de/mod.rs

@@ -12,7 +12,7 @@ mod from_primitive;
 /// `Deserializer` error.
 pub trait Error: Sized + error::Error {
     /// Raised when there is general error when deserializing a type.
-    fn custom(msg: String) -> Self;
+    fn custom<T: Into<String>>(msg: T) -> Self;
 
     /// Raised when a `Deserialize` type unexpectedly hit the end of the stream.
     fn end_of_stream() -> Self;

serde/src/de/value.rs

@@ -50,7 +50,7 @@ pub enum Error {
 }
 
 impl de::Error for Error {
-    fn custom(msg: String) -> Self { Error::Custom(msg) }
+    fn custom<T: Into<String>>(msg: T) -> Self { Error::Custom(msg.into()) }
     fn end_of_stream() -> Self { Error::EndOfStream }
     fn invalid_type(ty: de::Type) -> Self { Error::InvalidType(ty) }
     fn invalid_value(msg: &str) -> Self { Error::InvalidValue(msg.to_owned()) }

serde/src/ser/mod.rs

@@ -10,7 +10,7 @@ pub mod impls;
 /// `Serializer` error.
 pub trait Error: Sized + error::Error {
     /// Raised when there is general error when deserializing a type.
-    fn custom(msg: String) -> Self;
+    fn custom<T: Into<String>>(msg: T) -> Self;
 
     /// Raised when a `Serialize` was passed an incorrect value.
     fn invalid_value(msg: &str) -> Self {