Validate enum types

[lgfa29]

Overview

Enum types often have specific values they can take. For example, DiskBackendType can only be "local" or "distributed". When receiving external input, it is useful to validate that a value is actually a valid enum variant, so the SDK could provide validation methods like:

func (v DiskBackendType) Valid() bool {
	switch v {
	case DiskBackendTypeLocal, DiskBackendTypeDistributed:
		return true
	}
	return false
}

Now users can just cast an input and have the SDK validate it:

t := oxide.DiskBackendType(input)
if !t.Valid() {
    return fmt.Errorf("invalid disk type")
}

Implementation details

No response

Anything else you would like to add?

No response