Function decode_into 

pub fn decode_into(input: &[u8], output: &mut [u8]) -> Result<usize, HexError>

Constant-Time Hex Decoding

Arguments

• input - The hex-encoded slice to decode into output.
• output - The output buffer which the input is decoded into. This must be at least input.len() / 2 in size.

Errors

• HexError::Size: The output could not fit the decoded input, or the input was of invalid length.
• HexError::Encoding: An invalid character was encountered.

Returns

The amount of data which was decoded (input.len() / 2).