Use implicit capture syntax in format_args

This updates the standard library's documentation to use the new syntax. The
documentation is worthwhile to update as it should be more idiomatic
(particularly for features like this, which are nice for users to get acquainted
with). The general codebase is likely more hassle than benefit to update: it'll
hurt git blame, and generally updates can be done by folks updating the code if
(and when) that makes things more readable with the new format.

A few places in the compiler and library code are updated (mostly just due to
already having been done when this commit was first authored).

18 files changed, 24 insertions, 26 deletions

diff --git a/library/std/src/sys/sgx/abi/mod.rs b/library/std/src/sys/sgx/abi/mod.rs
index 5df08a4ff59..9508c387415 100644
--- a/library/std/src/sys/sgx/abi/mod.rs
+++ b/library/std/src/sys/sgx/abi/mod.rs
@@ -95,7 +95,7 @@ extern "C" fn entry(p1: u64, p2: u64, p3: u64, secondary: bool, p4: u64, p5: u64
 pub(super) fn exit_with_code(code: isize) -> ! {
     if code != 0 {
         if let Some(mut out) = panic::SgxPanicOutput::new() {
-            let _ = write!(out, "Exited with status code {}", code);
+            let _ = write!(out, "Exited with status code {code}");
         }
     }
     usercalls::exit(code != 0);
diff --git a/library/std/src/sys/sgx/abi/usercalls/mod.rs b/library/std/src/sys/sgx/abi/usercalls/mod.rs
index a6a659df291..4030355f135 100644
--- a/library/std/src/sys/sgx/abi/usercalls/mod.rs
+++ b/library/std/src/sys/sgx/abi/usercalls/mod.rs
@@ -83,7 +83,7 @@ pub fn close(fd: Fd) {
 
 fn string_from_bytebuffer(buf: &alloc::UserRef<ByteBuffer>, usercall: &str, arg: &str) -> String {
     String::from_utf8(buf.copy_user_buffer())
-        .unwrap_or_else(|_| rtabort!("Usercall {}: expected {} to be valid UTF-8", usercall, arg))
+        .unwrap_or_else(|_| rtabort!("Usercall {usercall}: expected {arg} to be valid UTF-8"))
 }
 
 /// Usercall `bind_stream`. See the ABI documentation for more information.
@@ -287,7 +287,7 @@ fn check_os_error(err: Result) -> i32 {
     {
         err
     } else {
-        rtabort!("Usercall: returned invalid error value {}", err)
+        rtabort!("Usercall: returned invalid error value {err}")
     }
 }
 
diff --git a/library/std/src/sys/sgx/abi/usercalls/raw.rs b/library/std/src/sys/sgx/abi/usercalls/raw.rs
index b0e6a6aaed7..4267b96ccd5 100644
--- a/library/std/src/sys/sgx/abi/usercalls/raw.rs
+++ b/library/std/src/sys/sgx/abi/usercalls/raw.rs
@@ -132,7 +132,7 @@ impl<T: RegisterArgument> RegisterArgument for Option<NonNull<T>> {
 
 impl ReturnValue for ! {
     fn from_registers(call: &'static str, _regs: (Register, Register)) -> Self {
-        rtabort!("Usercall {}: did not expect to be re-entered", call);
+        rtabort!("Usercall {call}: did not expect to be re-entered");
     }
 }
 
diff --git a/library/std/src/sys/sgx/net.rs b/library/std/src/sys/sgx/net.rs
index d14990c6877..feb0b62dcd1 100644
--- a/library/std/src/sys/sgx/net.rs
+++ b/library/std/src/sys/sgx/net.rs
@@ -501,7 +501,7 @@ impl<'a> TryFrom<(&'a str, u16)> for LookupHost {
     type Error = io::Error;
 
     fn try_from((host, port): (&'a str, u16)) -> io::Result<LookupHost> {
-        LookupHost::new(format!("{}:{}", host, port))
+        LookupHost::new(format!("{host}:{port}"))
     }
 }
 
diff --git a/library/std/src/sys/sgx/os.rs b/library/std/src/sys/sgx/os.rs
index 5f8b8def7c6..5da0257f35d 100644
--- a/library/std/src/sys/sgx/os.rs
+++ b/library/std/src/sys/sgx/os.rs
@@ -22,7 +22,7 @@ pub fn error_string(errno: i32) -> String {
     if errno == RESULT_SUCCESS {
         "operation successful".into()
     } else if ((Error::UserRangeStart as _)..=(Error::UserRangeEnd as _)).contains(&errno) {
-        format!("user-specified error {:08x}", errno)
+        format!("user-specified error {errno:08x}")
     } else {
         decode_error_kind(errno).as_str().into()
     }
diff --git a/library/std/src/sys/sgx/stdio.rs b/library/std/src/sys/sgx/stdio.rs
index 8ccf043b5b5..2e680e740fd 100644
--- a/library/std/src/sys/sgx/stdio.rs
+++ b/library/std/src/sys/sgx/stdio.rs
@@ -83,6 +83,6 @@ pub unsafe extern "C" fn __rust_print_err(m: *mut u8, s: i32) {
     }
     let buf = unsafe { slice::from_raw_parts(m as *const u8, s as _) };
     if let Ok(s) = str::from_utf8(&buf[..buf.iter().position(|&b| b == 0).unwrap_or(buf.len())]) {
-        eprint!("{}", s);
+        eprint!("{s}");
     }
 }
diff --git a/library/std/src/sys/solid/mod.rs b/library/std/src/sys/solid/mod.rs
index 2082c940153..049460755d6 100644
--- a/library/std/src/sys/solid/mod.rs
+++ b/library/std/src/sys/solid/mod.rs
@@ -87,7 +87,7 @@ pub fn hashmap_random_keys() -> (u64, u64) {
     unsafe {
         let mut out = crate::mem::MaybeUninit::<[u64; 2]>::uninit();
         let result = abi::SOLID_RNG_SampleRandomBytes(out.as_mut_ptr() as *mut u8, 16);
-        assert_eq!(result, 0, "SOLID_RNG_SampleRandomBytes failed: {}", result);
+        assert_eq!(result, 0, "SOLID_RNG_SampleRandomBytes failed: {result}");
         let [x1, x2] = out.assume_init();
         (x1, x2)
     }
diff --git a/library/std/src/sys/solid/net.rs b/library/std/src/sys/solid/net.rs
index a43407bd0f8..faeda5a854d 100644
--- a/library/std/src/sys/solid/net.rs
+++ b/library/std/src/sys/solid/net.rs
@@ -157,7 +157,7 @@ pub fn cvt_gai(err: c_int) -> io::Result<()> {
         };
         Err(io::Error::new(
             io::ErrorKind::Uncategorized,
-            &format!("failed to lookup address information: {}", msg)[..],
+            &format!("failed to lookup address information: {msg}")[..],
         ))
     }
 }
diff --git a/library/std/src/sys/solid/os.rs b/library/std/src/sys/solid/os.rs
index 22239e1fa8e..127cca3acca 100644
--- a/library/std/src/sys/solid/os.rs
+++ b/library/std/src/sys/solid/os.rs
@@ -26,7 +26,7 @@ pub fn errno() -> i32 {
 }
 
 pub fn error_string(errno: i32) -> String {
-    if let Some(name) = error::error_name(errno) { name.to_owned() } else { format!("{}", errno) }
+    if let Some(name) = error::error_name(errno) { name.to_owned() } else { format!("{errno}") }
 }
 
 pub fn getcwd() -> io::Result<PathBuf> {
diff --git a/library/std/src/sys/unix/net.rs b/library/std/src/sys/unix/net.rs
index 61c15ecd85d..e6fd9a0c827 100644
--- a/library/std/src/sys/unix/net.rs
+++ b/library/std/src/sys/unix/net.rs
@@ -54,7 +54,7 @@ pub fn cvt_gai(err: c_int) -> io::Result<()> {
 
     Err(io::Error::new(
         io::ErrorKind::Uncategorized,
-        &format!("failed to lookup address information: {}", detail)[..],
+        &format!("failed to lookup address information: {detail}")[..],
     ))
 }
 
diff --git a/library/std/src/sys/unix/os_str/tests.rs b/library/std/src/sys/unix/os_str/tests.rs
index 37967378155..213277f01f2 100644
--- a/library/std/src/sys/unix/os_str/tests.rs
+++ b/library/std/src/sys/unix/os_str/tests.rs
@@ -4,7 +4,7 @@ use super::*;
 fn slice_debug_output() {
     let input = Slice::from_u8_slice(b"\xF0hello,\tworld");
     let expected = r#""\xF0hello,\tworld""#;
-    let output = format!("{:?}", input);
+    let output = format!("{input:?}");
 
     assert_eq!(output, expected);
 }
diff --git a/library/std/src/sys/unix/process/process_fuchsia.rs b/library/std/src/sys/unix/process/process_fuchsia.rs
index 09bfd9680f5..e3347ab12a7 100644
--- a/library/std/src/sys/unix/process/process_fuchsia.rs
+++ b/library/std/src/sys/unix/process/process_fuchsia.rs
@@ -211,7 +211,7 @@ impl Process {
                     return Ok(None);
                 }
                 _ => {
-                    panic!("Failed to wait on process handle: {}", status);
+                    panic!("Failed to wait on process handle: {status}");
                 }
             }
             zx_cvt(zx_object_get_info(
diff --git a/library/std/src/sys/unix/process/process_unix.rs b/library/std/src/sys/unix/process/process_unix.rs
index 07a0339c066..9c477e5addc 100644
--- a/library/std/src/sys/unix/process/process_unix.rs
+++ b/library/std/src/sys/unix/process/process_unix.rs
@@ -120,7 +120,7 @@ impl Command {
                 Err(ref e) if e.kind() == ErrorKind::Interrupted => {}
                 Err(e) => {
                     assert!(p.wait().is_ok(), "wait() should either return Ok or panic");
-                    panic!("the CLOEXEC pipe failed: {:?}", e)
+                    panic!("the CLOEXEC pipe failed: {e:?}")
                 }
                 Ok(..) => {
                     // pipe I/O up to PIPE_BUF bytes should be atomic
@@ -682,15 +682,15 @@ impl From<c_int> for ExitStatus {
 impl fmt::Display for ExitStatus {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         if let Some(code) = self.code() {
-            write!(f, "exit status: {}", code)
+            write!(f, "exit status: {code}")
         } else if let Some(signal) = self.signal() {
             if self.core_dumped() {
-                write!(f, "signal: {} (core dumped)", signal)
+                write!(f, "signal: {signal} (core dumped)")
             } else {
-                write!(f, "signal: {}", signal)
+                write!(f, "signal: {signal}")
             }
         } else if let Some(signal) = self.stopped_signal() {
-            write!(f, "stopped (not terminated) by signal: {}", signal)
+            write!(f, "stopped (not terminated) by signal: {signal}")
         } else if self.continued() {
             write!(f, "continued (WIFCONTINUED)")
         } else {
diff --git a/library/std/src/sys/unix/process/process_vxworks.rs b/library/std/src/sys/unix/process/process_vxworks.rs
index 56ed6cfeb6a..016bc20ec0a 100644
--- a/library/std/src/sys/unix/process/process_vxworks.rs
+++ b/library/std/src/sys/unix/process/process_vxworks.rs
@@ -239,10 +239,10 @@ impl From<c_int> for ExitStatus {
 impl fmt::Display for ExitStatus {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         if let Some(code) = self.code() {
-            write!(f, "exit code: {}", code)
+            write!(f, "exit code: {code}")
         } else {
             let signal = self.signal().unwrap();
-            write!(f, "signal: {}", signal)
+            write!(f, "signal: {signal}")
         }
     }
 }
diff --git a/library/std/src/sys/unix/rand.rs b/library/std/src/sys/unix/rand.rs
index 7a3f6b0d95a..17e8efbe097 100644
--- a/library/std/src/sys/unix/rand.rs
+++ b/library/std/src/sys/unix/rand.rs
@@ -82,7 +82,7 @@ mod imp {
                 } else if err == libc::EAGAIN {
                     return false;
                 } else {
-                    panic!("unexpected getrandom error: {}", err);
+                    panic!("unexpected getrandom error: {err}");
                 }
             } else {
                 read += result as usize;
diff --git a/library/std/src/sys/windows/os.rs b/library/std/src/sys/windows/os.rs
index 5f8556c3bc3..450bceae000 100644
--- a/library/std/src/sys/windows/os.rs
+++ b/library/std/src/sys/windows/os.rs
@@ -64,7 +64,7 @@ pub fn error_string(mut errnum: i32) -> String {
         if res == 0 {
             // Sometimes FormatMessageW can fail e.g., system doesn't like langId,
             let fm_err = errno();
-            return format!("OS Error {} (FormatMessageW() returned error {})", errnum, fm_err);
+            return format!("OS Error {errnum} (FormatMessageW() returned error {fm_err})");
         }
 
         match String::from_utf16(&buf[..res]) {
diff --git a/library/std/src/sys/windows/process/tests.rs b/library/std/src/sys/windows/process/tests.rs
index d18c3d855bc..d8c9beb0c19 100644
--- a/library/std/src/sys/windows/process/tests.rs
+++ b/library/std/src/sys/windows/process/tests.rs
@@ -121,9 +121,7 @@ fn windows_env_unicode_case() {
             assert_eq!(
                 env::var(key).ok(),
                 value.map(|s| s.to_string_lossy().into_owned()),
-                "command environment mismatch: {} {}",
-                a,
-                b
+                "command environment mismatch: {a} {b}",
             );
         }
     }
diff --git a/library/std/src/sys/windows/thread_parker.rs b/library/std/src/sys/windows/thread_parker.rs
index 5a8011a9588..5888ee8e34b 100644
--- a/library/std/src/sys/windows/thread_parker.rs
+++ b/library/std/src/sys/windows/thread_parker.rs
@@ -230,7 +230,7 @@ fn keyed_event_handle() -> c::HANDLE {
                     0,
                 ) {
                     c::STATUS_SUCCESS => {}
-                    r => panic!("Unable to create keyed event handle: error {}", r),
+                    r => panic!("Unable to create keyed event handle: error {r}"),
                 }
             }
             match HANDLE.compare_exchange(INVALID, handle as usize, Relaxed, Relaxed) {