glib:key-file-double (keyfile group key)

keyfile -- a g:key-file instance
group -- a string for the group name
key -- a string for the key
value -- a number coerced to a double float for the value associated with the key as a double float

Gets or sets the value associated with key under group as a double float. If group is nil, the start group is used. If key cannot be found when it is set, the key is created. If key cannot be found when it is retrieved, 0.0d0 is returned. Likewise, if the value associated with key cannot be interpreted as a double float then 0.0d0 is returned.