Rollup merge of #150188 - yotamofek:pr/dogfood-strip-circumfix, r=Kivooeo

Dogfood `strip_circumfix`

cc rust-lang/rust#147946
Truth be told, I expected to find more places where this can be used in the compiler.
Seems cargo, clippy and rustfmt can use this much more frequently, but I'll have to wait (I think?) for the next two-way sync to be able to dogfood it in those repos.

compiler/rustc_metadata/src/errors.rs

@@ -251,9 +251,7 @@ pub fn new(libname: &'a str, verbatim: bool) -> Self {
         // if it looks like the user has provided a complete filename rather just the bare lib name,
         // then provide a note that they might want to try trimming the name
         let suggested_name = if !verbatim {
-            if let Some(libname) = libname.strip_prefix("lib")
-                && let Some(libname) = libname.strip_suffix(".a")
-            {
+            if let Some(libname) = libname.strip_circumfix("lib", ".a") {
                 // this is a unix style filename so trim prefix & suffix
                 Some(libname)
             } else if let Some(libname) = libname.strip_suffix(".lib") {

compiler/rustc_metadata/src/lib.rs

@@ -10,6 +10,7 @@
 #![feature(never_type)]
 #![feature(proc_macro_internals)]
 #![feature(result_option_map_or_default)]
+#![feature(strip_circumfix)]
 #![feature(trusted_len)]
 // tidy-alphabetical-end
 

compiler/rustc_trait_selection/src/error_reporting/infer/mod.rs

@@ -1758,8 +1758,7 @@ pub fn type_error_additional_suggestions(
                 // specify a byte literal
                 (ty::Uint(ty::UintTy::U8), ty::Char) => {
                     if let Ok(code) = self.tcx.sess().source_map().span_to_snippet(span)
-                        && let Some(code) =
-                            code.strip_prefix('\'').and_then(|s| s.strip_suffix('\''))
+                        && let Some(code) = code.strip_circumfix('\'', '\'')
                         // forbid all Unicode escapes
                         && !code.starts_with("\\u")
                         // forbids literal Unicode characters beyond ASCII
@@ -1776,7 +1775,7 @@ pub fn type_error_additional_suggestions(
                 // specify a character literal (issue #92479)
                 (ty::Char, ty::Ref(_, r, _)) if r.is_str() => {
                     if let Ok(code) = self.tcx.sess().source_map().span_to_snippet(span)
-                        && let Some(code) = code.strip_prefix('"').and_then(|s| s.strip_suffix('"'))
+                        && let Some(code) = code.strip_circumfix('"', '"')
                         && code.chars().count() == 1
                     {
                         suggestions.push(TypeErrorAdditionalDiags::MeantCharLiteral {

compiler/rustc_trait_selection/src/lib.rs

@@ -22,6 +22,7 @@
 #![feature(iter_intersperse)]
 #![feature(iterator_try_reduce)]
 #![feature(never_type)]
+#![feature(strip_circumfix)]
 #![feature(try_blocks)]
 #![feature(unwrap_infallible)]
 #![feature(yeet_expr)]