From e723fe1713b9db2ac7e3250ec8efe742cbcd46fe Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Gabriel=20Bj=C3=B8rnager=20Jensen?= Date: Mon, 23 Sep 2024 11:54:41 +0200 Subject: [PATCH] Mark and implement 'make_ascii_uppercase' and 'make_ascii_lowercase' in '[u8]' and 'str' as const; --- library/core/src/lib.rs | 2 ++ library/core/src/slice/ascii.rs | 18 ++++++++++++++---- library/core/src/str/mod.rs | 6 ++++-- 3 files changed, 20 insertions(+), 6 deletions(-) diff --git a/library/core/src/lib.rs b/library/core/src/lib.rs index a30b57c19d402..0ed81240f6aa1 100644 --- a/library/core/src/lib.rs +++ b/library/core/src/lib.rs @@ -133,6 +133,7 @@ #![feature(const_ipv4)] #![feature(const_ipv6)] #![feature(const_likely)] +#![feature(const_make_ascii)] #![feature(const_maybe_uninit_assume_init)] #![feature(const_nonnull_new)] #![feature(const_num_midpoint)] @@ -151,6 +152,7 @@ #![feature(const_slice_from_raw_parts_mut)] #![feature(const_slice_from_ref)] #![feature(const_slice_split_at_mut)] +#![feature(const_str_as_mut)] #![feature(const_str_from_utf8_unchecked_mut)] #![feature(const_strict_overflow_ops)] #![feature(const_swap)] diff --git a/library/core/src/slice/ascii.rs b/library/core/src/slice/ascii.rs index d1ea52fab6b87..8f8050fdc3aaf 100644 --- a/library/core/src/slice/ascii.rs +++ b/library/core/src/slice/ascii.rs @@ -67,10 +67,15 @@ impl [u8] { /// /// [`to_ascii_uppercase`]: #method.to_ascii_uppercase #[stable(feature = "ascii_methods_on_intrinsics", since = "1.23.0")] + #[rustc_const_unstable(feature = "const_make_ascii", issue = "130698")] #[inline] - pub fn make_ascii_uppercase(&mut self) { - for byte in self { + pub const fn make_ascii_uppercase(&mut self) { + // FIXME(const-hack): We would like to simply iterate using `for` loops but this isn't currently allowed in constant expressions. + let mut i = 0; + while i < self.len() { + let byte = &mut self[i]; byte.make_ascii_uppercase(); + i += 1; } } @@ -84,10 +89,15 @@ impl [u8] { /// /// [`to_ascii_lowercase`]: #method.to_ascii_lowercase #[stable(feature = "ascii_methods_on_intrinsics", since = "1.23.0")] + #[rustc_const_unstable(feature = "const_make_ascii", issue = "130698")] #[inline] - pub fn make_ascii_lowercase(&mut self) { - for byte in self { + pub const fn make_ascii_lowercase(&mut self) { + // FIXME(const-hack): We would like to simply iterate using `for` loops but this isn't currently allowed in constant expressions. + let mut i = 0; + while i < self.len() { + let byte = &mut self[i]; byte.make_ascii_lowercase(); + i += 1; } } diff --git a/library/core/src/str/mod.rs b/library/core/src/str/mod.rs index 300dde3dd4396..3d535214637f6 100644 --- a/library/core/src/str/mod.rs +++ b/library/core/src/str/mod.rs @@ -2473,8 +2473,9 @@ impl str { /// assert_eq!("GRüßE, JüRGEN ❤", s); /// ``` #[stable(feature = "ascii_methods_on_intrinsics", since = "1.23.0")] + #[rustc_const_unstable(feature = "const_make_ascii", issue = "130698")] #[inline] - pub fn make_ascii_uppercase(&mut self) { + pub const fn make_ascii_uppercase(&mut self) { // SAFETY: changing ASCII letters only does not invalidate UTF-8. let me = unsafe { self.as_bytes_mut() }; me.make_ascii_uppercase() @@ -2500,8 +2501,9 @@ impl str { /// assert_eq!("grÜße, jÜrgen ❤", s); /// ``` #[stable(feature = "ascii_methods_on_intrinsics", since = "1.23.0")] + #[rustc_const_unstable(feature = "const_make_ascii", issue = "130698")] #[inline] - pub fn make_ascii_lowercase(&mut self) { + pub const fn make_ascii_lowercase(&mut self) { // SAFETY: changing ASCII letters only does not invalidate UTF-8. let me = unsafe { self.as_bytes_mut() }; me.make_ascii_lowercase()