Replace unnecessary exchange util.

Signed-off-by: Jason Volk <jason@zemos.net>

src/core/info/rustc.rs

@@ -5,11 +5,10 @@
 
 use std::{
 	collections::BTreeMap,
+	mem::replace,
 	sync::{Mutex, OnceLock},
 };
 
-use crate::utils::exchange;
-
 // Capture rustc version during compilation.
 tuwunel_macros::rustc_version! {}
 
@@ -54,7 +53,7 @@ fn append_features(features: &mut Vec<&'static str>, flags: &[&'static str]) {
 	for flag in flags {
 		let is_cfg = *flag == "--cfg";
 		let is_feature = flag.starts_with("feature=");
-		if exchange(&mut next_is_cfg, is_cfg) && is_feature {
+		if replace(&mut next_is_cfg, is_cfg) && is_feature {
 			if let Some(feature) = flag
 				.split_once('=')
 				.map(|(_, feature)| feature.trim_matches('"'))

src/core/utils/mod.rs

@@ -42,9 +42,6 @@ pub use self::{
 	},
 };
 
-#[inline]
-pub fn exchange<T>(state: &mut T, source: T) -> T { std::mem::replace(state, source) }
-
 #[macro_export]
 macro_rules! extract_variant {
 	( $e:expr_2021, $( $variant:path )|* ) => {

src/core/utils/string.rs

@@ -4,8 +4,10 @@ mod tests;
 mod unquote;
 mod unquoted;
 
+use std::mem::replace;
+
 pub use self::{between::Between, split::SplitInfallible, unquote::Unquote, unquoted::Unquoted};
-use crate::{Result, smallstr::SmallString, utils::exchange};
+use crate::{Result, smallstr::SmallString};
 
 pub const EMPTY: &str = "";
 
@@ -76,7 +78,7 @@ where
 		.map(char::from)
 		.try_for_each(|ch| {
 			let m = ch.is_ascii_uppercase();
-			let s = exchange(&mut state, !m);
+			let s = replace(&mut state, !m);
 			if m && s {
 				output.write_char('_')?;
 			}