read_at with Rust

read_at.rs

#[cfg(any(windows))]
fn load_exact_bytes_at(buffer: &mut Vec<u8>, file: &File, offset: u64) {
    use std::os::windows::fs::FileExt;
    let mut data_read = 0;
    while data_read < buffer.len() {
        data_read += file.seek_read(buffer, offset).unwrap();
    }
}

#[cfg(any(unix))]
fn load_exact_bytes_at(buffer: &mut Vec<u8>, file: &File, offset: u64) {
    use std::os::unix::fs::FileExt;
    let mut data_read = 0;
    while data_read < buffer.len() {
        data_read += file.read_at(buffer, offset).unwrap();
    }
}