fn calcSizeUpperBound(decoder_with_ignore: *const Base64DecoderWithIgnore, source_len: usize) Error!usize

Return the maximum possible decoded size for a given input length - The actual length may be less if the input includes padding InvalidPadding is returned if the input length is not valid.

Parameters

decoder_with_ignore: *const Base64DecoderWithIgnore,
source_len: usize,