Rust u8数组转16进制字符串

把常用的c++转16进制的函数用rust重写了一下。

static HEX_TABLE :[char;16] = ['0','1','2','3','4','5','6','7','8','9',
                                        'A','B','C','D','E','F'];

fn to_hex(data : impl AsRef<[u8]>) -> String {
    let data = data.as_ref();
    let len = data.len();
    let mut res = String::with_capacity(len * 2);

    for i in 0..len {
        res.push(HEX_TABLE[usize::from(data[i] >> 4)] );
        res.push(HEX_TABLE[usize::from(data[i] & 0x0F)]);
    }
    res
}

Vec的需要稍微改一下