fixup! Add TryFrom to convert repr to enum

msrv compatible doctest

impl/Cargo.toml

@@ -34,6 +34,7 @@ rustc_version = { version = "0.4", optional = true }
 [dev-dependencies]
 derive_more = { path = "..", features = ["full"] }
 itertools = "0.11.0"
+rustversion = "1.0"
 
 [badges]
 github = { repository = "JelteF/derive_more", workflow = "CI" }

impl/doc/try_from.md

@@ -7,8 +7,9 @@ Only field-less variants can be constructed from their variant, therefor the `Tr
 ## Example usage
 
 ```rust
+# #[rustversion::since(1.66)]
+# mod discriminant_on_non_unit_enum {
 # use derive_more::TryFrom;
-#
 #[derive(TryFrom, Debug, PartialEq)]
 #[repr(u32)]
 enum Enum {
@@ -18,10 +19,18 @@ enum Enum {
     Empty{},
 }
 
+# #[rustversion::since(1.66)]
+# pub fn test(){
 assert_eq!(Enum::Implicit, Enum::try_from(0).unwrap());
 assert_eq!(Enum::Explicit, Enum::try_from(5).unwrap());
 assert_eq!(Enum::Empty{}, Enum::try_from(7).unwrap());
 
 // variants with fields are not supported
 assert!(Enum::try_from(6).is_err());
+# }
+# }
+# // We need to use a `function` declaration, because we cannot put `rustversion` on a statement.
+# #[rustversion::since(1.66)] use discriminant_on_non_unit_enum::test;
+# #[rustversion::before(1.66)] fn test() {}
+# test();
 ```