Rollup merge of #145756 - okaneco:stabilize_char_boundary, r=scottmcm

str: Stabilize `round_char_boundary` feature

Closes https://github.com/rust-lang/rust/issues/93743
FCP completed https://github.com/rust-lang/rust/issues/93743#issuecomment-3168382171

10 files changed, 22 insertions, 26 deletions

diff --git a/compiler/rustc_middle/src/lib.rs b/compiler/rustc_middle/src/lib.rs
index cf0549fa668..5023b2740ef 100644
--- a/compiler/rustc_middle/src/lib.rs
+++ b/compiler/rustc_middle/src/lib.rs
@@ -29,6 +29,7 @@
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::direct_use_of_rustc_type_ir)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![cfg_attr(bootstrap, feature(round_char_boundary))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(allocator_api)]
@@ -51,7 +52,6 @@
 #![feature(negative_impls)]
 #![feature(never_type)]
 #![feature(ptr_alignment_type)]
-#![feature(round_char_boundary)]
 #![feature(rustc_attrs)]
 #![feature(rustdoc_internals)]
 #![feature(sized_hierarchy)]
diff --git a/compiler/rustc_span/src/lib.rs b/compiler/rustc_span/src/lib.rs
index d647ec28aae..ae6755f0764 100644
--- a/compiler/rustc_span/src/lib.rs
+++ b/compiler/rustc_span/src/lib.rs
@@ -17,6 +17,7 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(round_char_boundary))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(array_windows)]
@@ -26,7 +27,6 @@
 #![feature(map_try_insert)]
 #![feature(negative_impls)]
 #![feature(read_buf)]
-#![feature(round_char_boundary)]
 #![feature(rustc_attrs)]
 #![feature(rustdoc_internals)]
 // tidy-alphabetical-end
diff --git a/library/alloctests/tests/lib.rs b/library/alloctests/tests/lib.rs
index 447af240a4b..bf446ae1ba4 100644
--- a/library/alloctests/tests/lib.rs
+++ b/library/alloctests/tests/lib.rs
@@ -24,7 +24,6 @@
 #![feature(inplace_iteration)]
 #![feature(iter_advance_by)]
 #![feature(iter_next_chunk)]
-#![feature(round_char_boundary)]
 #![feature(slice_partition_dedup)]
 #![feature(string_from_utf8_lossy_owned)]
 #![feature(string_remove_matches)]
diff --git a/library/core/src/str/mod.rs b/library/core/src/str/mod.rs
index 1a055a0a5ad..f1db385e212 100644
--- a/library/core/src/str/mod.rs
+++ b/library/core/src/str/mod.rs
@@ -396,7 +396,6 @@ impl str {
     /// # Examples
     ///
     /// ```
-    /// #![feature(round_char_boundary)]
     /// let s = "❤️🧡💛💚💙💜";
     /// assert_eq!(s.len(), 26);
     /// assert!(!s.is_char_boundary(13));
@@ -405,7 +404,8 @@ impl str {
     /// assert_eq!(closest, 10);
     /// assert_eq!(&s[..closest], "❤️🧡");
     /// ```
-    #[unstable(feature = "round_char_boundary", issue = "93743")]
+    #[stable(feature = "round_char_boundary", since = "CURRENT_RUSTC_VERSION")]
+    #[rustc_const_stable(feature = "round_char_boundary", since = "CURRENT_RUSTC_VERSION")]
     #[inline]
     pub const fn floor_char_boundary(&self, index: usize) -> usize {
         if index >= self.len() {
@@ -439,7 +439,6 @@ impl str {
     /// # Examples
     ///
     /// ```
-    /// #![feature(round_char_boundary)]
     /// let s = "❤️🧡💛💚💙💜";
     /// assert_eq!(s.len(), 26);
     /// assert!(!s.is_char_boundary(13));
@@ -448,7 +447,8 @@ impl str {
     /// assert_eq!(closest, 14);
     /// assert_eq!(&s[..closest], "❤️🧡💛");
     /// ```
-    #[unstable(feature = "round_char_boundary", issue = "93743")]
+    #[stable(feature = "round_char_boundary", since = "CURRENT_RUSTC_VERSION")]
+    #[rustc_const_stable(feature = "round_char_boundary", since = "CURRENT_RUSTC_VERSION")]
     #[inline]
     pub const fn ceil_char_boundary(&self, index: usize) -> usize {
         if index >= self.len() {
diff --git a/library/std/src/lib.rs b/library/std/src/lib.rs
index 9fc84128cb2..3771699c59f 100644
--- a/library/std/src/lib.rs
+++ b/library/std/src/lib.rs
@@ -263,7 +263,6 @@
     all(target_vendor = "fortanix", target_env = "sgx"),
     feature(slice_index_methods, coerce_unsized, sgx_platform)
 )]
-#![cfg_attr(any(windows, target_os = "uefi"), feature(round_char_boundary))]
 #![cfg_attr(target_family = "wasm", feature(stdarch_wasm_atomic_wait))]
 #![cfg_attr(target_arch = "wasm64", feature(simd_wasm64))]
 //
diff --git a/src/librustdoc/lib.rs b/src/librustdoc/lib.rs
index e2682045ab4..cd29b096ccf 100644
--- a/src/librustdoc/lib.rs
+++ b/src/librustdoc/lib.rs
@@ -1,4 +1,5 @@
 // tidy-alphabetical-start
+#![cfg_attr(bootstrap, feature(round_char_boundary))]
 #![doc(
     html_root_url = "https://doc.rust-lang.org/nightly/",
     html_playground_url = "https://play.rust-lang.org/"
@@ -13,7 +14,6 @@
 #![feature(if_let_guard)]
 #![feature(iter_advance_by)]
 #![feature(iter_intersperse)]
-#![feature(round_char_boundary)]
 #![feature(rustc_private)]
 #![feature(test)]
 #![warn(rustc::internal)]
diff --git a/src/tools/clippy/clippy_lints/src/lib.rs b/src/tools/clippy/clippy_lints/src/lib.rs
index d468993e744..c8594cf35e2 100644
--- a/src/tools/clippy/clippy_lints/src/lib.rs
+++ b/src/tools/clippy/clippy_lints/src/lib.rs
@@ -7,7 +7,7 @@
 #![feature(iter_intersperse)]
 #![feature(iter_partition_in_place)]
 #![feature(never_type)]
-#![feature(round_char_boundary)]
+#![cfg_attr(bootstrap, feature(round_char_boundary))]
 #![feature(rustc_private)]
 #![feature(stmt_expr_attributes)]
 #![feature(unwrap_infallible)]
diff --git a/src/tools/clippy/tests/ui/char_indices_as_byte_indices.fixed b/src/tools/clippy/tests/ui/char_indices_as_byte_indices.fixed
index 04c8f6782c5..375a101c2e3 100644
--- a/src/tools/clippy/tests/ui/char_indices_as_byte_indices.fixed
+++ b/src/tools/clippy/tests/ui/char_indices_as_byte_indices.fixed
@@ -1,4 +1,3 @@
-#![feature(round_char_boundary)]
 #![warn(clippy::char_indices_as_byte_indices)]
 
 trait StrExt {
diff --git a/src/tools/clippy/tests/ui/char_indices_as_byte_indices.rs b/src/tools/clippy/tests/ui/char_indices_as_byte_indices.rs
index 773a4fc65f1..eebc39962a2 100644
--- a/src/tools/clippy/tests/ui/char_indices_as_byte_indices.rs
+++ b/src/tools/clippy/tests/ui/char_indices_as_byte_indices.rs
@@ -1,4 +1,3 @@
-#![feature(round_char_boundary)]
 #![warn(clippy::char_indices_as_byte_indices)]
 
 trait StrExt {
diff --git a/src/tools/clippy/tests/ui/char_indices_as_byte_indices.stderr b/src/tools/clippy/tests/ui/char_indices_as_byte_indices.stderr
index e2b4c1db78c..fae81fd772d 100644
--- a/src/tools/clippy/tests/ui/char_indices_as_byte_indices.stderr
+++ b/src/tools/clippy/tests/ui/char_indices_as_byte_indices.stderr
@@ -1,12 +1,12 @@
 error: indexing into a string with a character position where a byte index is expected
-  --> tests/ui/char_indices_as_byte_indices.rs:13:24
+  --> tests/ui/char_indices_as_byte_indices.rs:12:24
    |
 LL |         let _ = prim[..idx];
    |                        ^^^
    |
    = note: a character can take up more than one byte, so they are not interchangeable
 note: position comes from the enumerate iterator
-  --> tests/ui/char_indices_as_byte_indices.rs:12:10
+  --> tests/ui/char_indices_as_byte_indices.rs:11:10
    |
 LL |     for (idx, _) in prim.chars().enumerate() {
    |          ^^^                     ^^^^^^^^^^^
@@ -19,14 +19,14 @@ LL +     for (idx, _) in prim.char_indices() {
    |
 
 error: passing a character position to a method that expects a byte index
-  --> tests/ui/char_indices_as_byte_indices.rs:15:23
+  --> tests/ui/char_indices_as_byte_indices.rs:14:23
    |
 LL |         prim.split_at(idx);
    |                       ^^^
    |
    = note: a character can take up more than one byte, so they are not interchangeable
 note: position comes from the enumerate iterator
-  --> tests/ui/char_indices_as_byte_indices.rs:12:10
+  --> tests/ui/char_indices_as_byte_indices.rs:11:10
    |
 LL |     for (idx, _) in prim.chars().enumerate() {
    |          ^^^                     ^^^^^^^^^^^
@@ -37,14 +37,14 @@ LL +     for (idx, _) in prim.char_indices() {
    |
 
 error: passing a character position to a method that expects a byte index
-  --> tests/ui/char_indices_as_byte_indices.rs:19:49
+  --> tests/ui/char_indices_as_byte_indices.rs:18:49
    |
 LL |         let _ = prim[..prim.floor_char_boundary(idx)];
    |                                                 ^^^
    |
    = note: a character can take up more than one byte, so they are not interchangeable
 note: position comes from the enumerate iterator
-  --> tests/ui/char_indices_as_byte_indices.rs:12:10
+  --> tests/ui/char_indices_as_byte_indices.rs:11:10
    |
 LL |     for (idx, _) in prim.chars().enumerate() {
    |          ^^^                     ^^^^^^^^^^^
@@ -55,14 +55,14 @@ LL +     for (idx, _) in prim.char_indices() {
    |
 
 error: indexing into a string with a character position where a byte index is expected
-  --> tests/ui/char_indices_as_byte_indices.rs:29:24
+  --> tests/ui/char_indices_as_byte_indices.rs:28:24
    |
 LL |         let _ = prim[..c.0];
    |                        ^^^
    |
    = note: a character can take up more than one byte, so they are not interchangeable
 note: position comes from the enumerate iterator
-  --> tests/ui/char_indices_as_byte_indices.rs:28:9
+  --> tests/ui/char_indices_as_byte_indices.rs:27:9
    |
 LL |     for c in prim.chars().enumerate() {
    |         ^                 ^^^^^^^^^^^
@@ -73,14 +73,14 @@ LL +     for c in prim.char_indices() {
    |
 
 error: passing a character position to a method that expects a byte index
-  --> tests/ui/char_indices_as_byte_indices.rs:31:23
+  --> tests/ui/char_indices_as_byte_indices.rs:30:23
    |
 LL |         prim.split_at(c.0);
    |                       ^^^
    |
    = note: a character can take up more than one byte, so they are not interchangeable
 note: position comes from the enumerate iterator
-  --> tests/ui/char_indices_as_byte_indices.rs:28:9
+  --> tests/ui/char_indices_as_byte_indices.rs:27:9
    |
 LL |     for c in prim.chars().enumerate() {
    |         ^                 ^^^^^^^^^^^
@@ -91,14 +91,14 @@ LL +     for c in prim.char_indices() {
    |
 
 error: indexing into a string with a character position where a byte index is expected
-  --> tests/ui/char_indices_as_byte_indices.rs:36:26
+  --> tests/ui/char_indices_as_byte_indices.rs:35:26
    |
 LL |         let _ = string[..idx];
    |                          ^^^
    |
    = note: a character can take up more than one byte, so they are not interchangeable
 note: position comes from the enumerate iterator
-  --> tests/ui/char_indices_as_byte_indices.rs:35:10
+  --> tests/ui/char_indices_as_byte_indices.rs:34:10
    |
 LL |     for (idx, _) in string.chars().enumerate() {
    |          ^^^                       ^^^^^^^^^^^
@@ -109,14 +109,14 @@ LL +     for (idx, _) in string.char_indices() {
    |
 
 error: passing a character position to a method that expects a byte index
-  --> tests/ui/char_indices_as_byte_indices.rs:38:25
+  --> tests/ui/char_indices_as_byte_indices.rs:37:25
    |
 LL |         string.split_at(idx);
    |                         ^^^
    |
    = note: a character can take up more than one byte, so they are not interchangeable
 note: position comes from the enumerate iterator
-  --> tests/ui/char_indices_as_byte_indices.rs:35:10
+  --> tests/ui/char_indices_as_byte_indices.rs:34:10
    |
 LL |     for (idx, _) in string.chars().enumerate() {
    |          ^^^                       ^^^^^^^^^^^