Make unicode-width an optional default dependency

Author: bjorn3

Cargo.toml

@@ -10,12 +10,14 @@ edition = "2021"
 rust-version = "1.66"
 
 [dependencies]
-unicode-width = "0.2.0"
+unicode-width = { version = "0.2.0", optional = true }
 std = { version = "1.0", package = "rustc-std-workspace-std", optional = true }
 core = { version = "1.0", package = "rustc-std-workspace-core", optional = true }
 
 [dev-dependencies]
 log = "0.4"
 
 [features]
+default = ["unicode"]
 rustc-dep-of-std = ["unicode-width/rustc-dep-of-std", "std", "core"]
+unicode = ["dep:unicode-width"]

src/lib.rs

@@ -104,7 +104,6 @@
 #[cfg(test)]
 #[macro_use]
 extern crate log;
-extern crate unicode_width;
 
 use self::Fail::*;
 use self::HasArg::*;
@@ -119,8 +118,21 @@ use std::iter::{repeat, IntoIterator};
 use std::result;
 use std::str::FromStr;
 
+#[cfg(feature = "unicode")]
 use unicode_width::UnicodeWidthStr;
 
+#[cfg(not(feature = "unicode"))]
+trait UnicodeWidthStr {
+    fn width(&self) -> usize;
+}
+
+#[cfg(not(feature = "unicode"))]
+impl UnicodeWidthStr for str {
+    fn width(&self) -> usize {
+        self.len()
+    }
+}
+
 #[cfg(test)]
 mod tests;