capi: inline format arguments

Closes #1285

Author: nyurik

regex-capi/src/error.rs

@@ -60,7 +60,7 @@ ffi_fn! {
 ffi_fn! {
     fn rure_error_message(err: *mut Error) -> *const c_char {
         let err = unsafe { &mut *err };
-        let cmsg = match CString::new(format!("{}", err)) {
+        let cmsg = match CString::new(format!("{err}")) {
             Ok(msg) => msg,
             Err(err) => {
                 // I guess this can probably happen if the regex itself has a

regex-capi/src/macros.rs

@@ -20,8 +20,8 @@ macro_rules! ffi_fn {
                     };
                     let _ = writeln!(
                         &mut io::stderr(),
-                        "panic unwind caught, aborting: {:?}",
-                        msg);
+                        "panic unwind caught, aborting: {msg:?}"
+                    );
                     unsafe { abort() }
                 }
             }

regex-capi/src/rure.rs

@@ -82,7 +82,7 @@ ffi_fn! {
         let re = rure_compile(
             pat, len, RURE_DEFAULT_FLAGS, ptr::null(), &mut err);
         if err.is_err() {
-            let _ = writeln!(&mut io::stderr(), "{}", err);
+            let _ = writeln!(&mut io::stderr(), "{err}");
             let _ = writeln!(
                 &mut io::stderr(), "aborting from rure_compile_must");
             unsafe { abort() }
@@ -579,7 +579,7 @@ ffi_fn! {
         let mut err = Error::new(ErrorKind::None);
         let esc = rure_escape(pat, len, &mut err);
         if err.is_err() {
-            let _ = writeln!(&mut io::stderr(), "{}", err);
+            let _ = writeln!(&mut io::stderr(), "{err}");
             let _ = writeln!(
                 &mut io::stderr(), "aborting from rure_escape_must");
             unsafe { abort() }