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// Original implementation taken from rust-memchr.
// Copyright 2015 Andrew Gallant, bluss and Nicolas Koch
pub fn memchr(needle: u8, haystack: &[u8]) -> Option<usize> {
let p = unsafe {
libc::memchr(
haystack.as_ptr() as *const libc::c_void,
needle as libc::c_int,
haystack.len(),
)
};
if p.is_null() { None } else { Some(p.addr() - haystack.as_ptr().addr()) }
}
pub fn memrchr(needle: u8, haystack: &[u8]) -> Option<usize> {
#[cfg(target_os = "linux")]
fn memrchr_specific(needle: u8, haystack: &[u8]) -> Option<usize> {
// GNU's memrchr() will - unlike memchr() - error if haystack is empty.
if haystack.is_empty() {
return None;
}
let p = unsafe {
libc::memrchr(
haystack.as_ptr() as *const libc::c_void,
needle as libc::c_int,
haystack.len(),
)
};
// FIXME: this should *likely* use `offset_from`, but more
// investigation is needed (including running tests in miri).
if p.is_null() { None } else { Some(p.addr() - haystack.as_ptr().addr()) }
}
#[cfg(not(target_os = "linux"))]
fn memrchr_specific(needle: u8, haystack: &[u8]) -> Option<usize> {
core::slice::memchr::memrchr(needle, haystack)
}
memrchr_specific(needle, haystack)
}
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