CheckDisallowed checks that no environment variables with the prefix are set that we don't know how or want to parse.

MustProcess is the same as Process but panics if an error occurs.

Process populates the specified struct based on environment variables.

ErrInvalidSpecification indicates that a specification is of the wrong type.

A ParseError occurs when an environment variable cannot be converted to the type required by a struct field during assignment.

Decoder has the same semantics as Setter, but takes higher precedence.

Setter is implemented by types can self-deserialize values.