encoding/base64 already skips \r and \n when decoding, so this package
must only deal with spaces and tabs. Those aren't nearly as common, so
we can add a fast path with bytes.ContainsAny to skip the costly alloc
and filtering code.
name old time/op new time/op delta
Decode-8 279µs ± 0% 259µs ± 1% -7.07% (p=0.002 n=6+6)
name old speed new speed delta
Decode-8 319MB/s ± 0% 343MB/s ± 1% +7.61% (p=0.002 n=6+6)
name old alloc/op new alloc/op delta
Decode-8 164kB ± 0% 74kB ± 0% -54.90% (p=0.002 n=6+6)
name old allocs/op new allocs/op delta
Decode-8 12.0 ± 0% 11.0 ± 0% -8.33% (p=0.002 n=6+6)