feature gate core::error

Author: jordens

Cargo.toml

@@ -7,14 +7,14 @@ license = "MIT OR Apache-2.0"
 edition = "2021"
 repository = "https://github.com/rust-embedded-community/menu"
 readme = "README.md"
-rust-version = "1.81.0"
 
 [dependencies]
 embedded-io = "0.6.1"
 noline = { version = "0.5.0", optional = true }
 
 [features]
 default = ["echo"]
+error-in-core = []  # requires rust 1.81.0
 echo = []
 
 [dev-dependencies]

src/lib.rs

@@ -133,6 +133,7 @@ impl core::fmt::Display for Error {
     }
 }
 
+#[cfg(feature = "error-in-core")]
 impl core::error::Error for Error {}
 
 /// Looks for the named parameter in the parameter list of the item, then