How to decode the input.
Unconditionally treat the input as if it were an OpenPGP message encoded using ASCII armor.
Unconditionally treat the input as if it were a binary OpenPGP message.
If input does not appear to be a binary encoded OpenPGP message, treat it as if it were encoded using ASCII armor.
This is the default.
type Error = Infallible
The type returned in the event of a conversion error.