Design documents query

[Aycrigg, Ben]

I have tried a couple of ways (using Fauxton with CouchDB 2.1.0) to retrieve 
Design documents only, but with no luck so far, meaning no documents returned. 
Can anyone tell me what is wrong with these?

// if the document structure contains the "views" Key:
function (doc) {
 if(doc.views)
 emit(doc._id, doc._rev);
}

// if the document ID starts with "_design":
function (doc) {
 if(doc._id.substring(0,7) == "_design")
 emit(doc._id, doc._rev);
}