make some fns const

Author: hkratz

portable/src/compat.rs

@@ -32,7 +32,7 @@ impl Utf8Error {
     /// ...
     #[inline]
     #[must_use]
-    pub fn valid_up_to(&self) -> usize {
+    pub const fn valid_up_to(&self) -> usize {
         self.valid_up_to
     }
 

portable/src/implementation/mod.rs

@@ -33,7 +33,9 @@ fn validate_utf8_compat_simd(input: &[u8]) -> Result<(), crate::compat::Utf8Erro
 
 // fallback method implementations
 #[inline]
-pub(crate) fn validate_utf8_basic_fallback(input: &[u8]) -> Result<(), crate::basic::Utf8Error> {
+pub(crate) const fn validate_utf8_basic_fallback(
+    input: &[u8],
+) -> Result<(), crate::basic::Utf8Error> {
     match core::str::from_utf8(input) {
         Ok(_) => Ok(()),
         Err(_) => Err(crate::basic::Utf8Error {}),

portable/src/implementation/simd.rs

@@ -471,6 +471,7 @@ impl SimdU8Value<32> for u8x32 {
 
     #[inline]
     fn prev1(self, prev: Self) -> Self {
+        // FIXME? this is more than we actually need. Not sure if AVX2 support this
         simd_swizzle!(
             self,
             prev,

portable/src/lib.rs

@@ -7,7 +7,6 @@
     clippy::nursery
 )]
 #![expect(clippy::redundant_pub_crate)] // check is broken (see e.g. https://github.com/rust-lang/rust-clippy/issues/5369)
-#![expect(clippy::missing_const_for_fn)] // not necessary most of the times
 #![deny(missing_docs)]
 #![cfg_attr(not(feature = "std"), no_std)]
 #![cfg_attr(docsrs, feature(doc_cfg))]