Accept owned and borrowed Regex

For performance, it is desirable to accept &Regex instead of Regex.
By changing changing to impl Borrow<Regex>, all existing code
remains valid, but &Regex is also accepted.

src/finder.rs

@@ -5,6 +5,8 @@ use crate::helper::has_executable_extension;
 use either::Either;
 #[cfg(feature = "regex")]
 use regex::Regex;
+#[cfg(feature = "regex")]
+use std::borrow::Borrow;
 use std::env;
 use std::ffi::OsStr;
 #[cfg(feature = "regex")]
@@ -81,7 +83,7 @@ impl Finder {
     #[cfg(feature = "regex")]
     pub fn find_re<T>(
         &self,
-        binary_regex: Regex,
+        binary_regex: impl Borrow<Regex>,
         paths: Option<T>,
         binary_checker: CompositeChecker,
     ) -> Result<impl Iterator<Item = PathBuf>>
@@ -99,7 +101,7 @@ impl Finder {
             .map(|e| e.path())
             .filter(move |p| {
                 if let Some(unicode_file_name) = p.file_name().unwrap().to_str() {
-                    binary_regex.is_match(unicode_file_name)
+                    binary_regex.borrow().is_match(unicode_file_name)
                 } else {
                     false
                 }

src/lib.rs

@@ -26,6 +26,8 @@ mod helper;
 
 #[cfg(feature = "regex")]
 use regex::Regex;
+#[cfg(feature = "regex")]
+use std::borrow::Borrow;
 use std::env;
 use std::fmt;
 use std::path;
@@ -87,7 +89,7 @@ pub fn which_all<T: AsRef<OsStr>>(binary_name: T) -> Result<impl Iterator<Item =
 /// assert_eq!(binaries, python_paths);
 /// ```
 #[cfg(feature = "regex")]
-pub fn which_re(regex: Regex) -> Result<impl Iterator<Item = path::PathBuf>> {
+pub fn which_re(regex: impl Borrow<Regex>) -> Result<impl Iterator<Item = path::PathBuf>> {
     which_re_in(regex, env::var_os("PATH"))
 }
 
@@ -124,7 +126,7 @@ where
 /// assert_eq!(binaries, python_paths);
 /// ```
 #[cfg(feature = "regex")]
-pub fn which_re_in<T>(regex: Regex, paths: Option<T>) -> Result<impl Iterator<Item = path::PathBuf>>
+pub fn which_re_in<T>(regex: impl Borrow<Regex>, paths: Option<T>) -> Result<impl Iterator<Item = path::PathBuf>>
 where
     T: AsRef<OsStr>,
 {

tests/basic.rs

@@ -162,6 +162,15 @@ fn test_which_re_in_without_matches() {
     assert_eq!(result, Vec::<PathBuf>::new())
 }
 
+#[test]
+#[cfg(all(unix, feature = "regex"))]
+fn test_which_re_accepts_owned_and_borrow() {
+    which::which_re(Regex::new(r".").unwrap());
+    which::which_re(&Regex::new(r".").unwrap());
+    which::which_re_in(Regex::new(r".").unwrap(), Some("pth"));
+    which::which_re_in(&Regex::new(r".").unwrap(), Some("pth"));
+}
+
 #[test]
 #[cfg(unix)]
 fn test_which_extension() {