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// Copyright 2026 Google LLC
// SPDX-License-Identifier: Apache-2.0
pub fn copy(dest: &mut [u8], source: *const u8) {
    let source = {
        let mut len = 0;

        let mut end = source;
        while unsafe { *end != 0 } {
            len += 1;
            end = unsafe { end.add(1) };
        }

        unsafe { std::slice::from_raw_parts(source, len + 1) }
    };

    for (dest, src) in dest.iter_mut().zip(source) {
        *dest = *src;
    }
}

fn main() {
    let a = [114, 117, 115, 116].as_ptr();
    let b = &mut [82, 85, 83, 84, 0];

    println!("{}", String::from_utf8_lossy(b));
    copy(b, a);
    println!("{}", String::from_utf8_lossy(b));
}