diff options
Diffstat (limited to 'library/alloc/src/str.rs')
| -rw-r--r-- | library/alloc/src/str.rs | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/library/alloc/src/str.rs b/library/alloc/src/str.rs index ade114678b7..3e23612d0c1 100644 --- a/library/alloc/src/str.rs +++ b/library/alloc/src/str.rs @@ -53,7 +53,7 @@ pub use core::str::{RSplit, Split}; pub use core::str::{RSplitN, SplitN}; #[stable(feature = "rust1", since = "1.0.0")] pub use core::str::{RSplitTerminator, SplitTerminator}; -#[unstable(feature = "utf8_chunks", issue = "99543")] +#[stable(feature = "utf8_chunks", since = "1.79.0")] pub use core::str::{Utf8Chunk, Utf8Chunks}; /// Note: `str` in `Concat<str>` is not meaningful here. @@ -375,14 +375,16 @@ impl str { // Safety: We have written only valid ASCII to our vec let mut s = unsafe { String::from_utf8_unchecked(out) }; - for (i, c) in rest[..].char_indices() { + for (i, c) in rest.char_indices() { if c == 'Σ' { // Σ maps to σ, except at the end of a word where it maps to ς. // This is the only conditional (contextual) but language-independent mapping // in `SpecialCasing.txt`, // so hard-code it rather than have a generic "condition" mechanism. // See https://github.com/rust-lang/rust/issues/26035 - map_uppercase_sigma(rest, i, &mut s) + let out_len = self.len() - rest.len(); + let sigma_lowercase = map_uppercase_sigma(&self, i + out_len); + s.push(sigma_lowercase); } else { match conversions::to_lower(c) { [a, '\0', _] => s.push(a), @@ -400,13 +402,13 @@ impl str { } return s; - fn map_uppercase_sigma(from: &str, i: usize, to: &mut String) { + fn map_uppercase_sigma(from: &str, i: usize) -> char { // See https://www.unicode.org/versions/Unicode7.0.0/ch03.pdf#G33992 // for the definition of `Final_Sigma`. debug_assert!('Σ'.len_utf8() == 2); let is_word_final = case_ignorable_then_cased(from[..i].chars().rev()) && !case_ignorable_then_cased(from[i + 2..].chars()); - to.push_str(if is_word_final { "ς" } else { "σ" }); + if is_word_final { 'ς' } else { 'σ' } } fn case_ignorable_then_cased<I: Iterator<Item = char>>(iter: I) -> bool { |