Abstract supertype of resources which are created at the beginning of a try statement and destroyed when the statement completes. Unlike an Obtainable resource, a single instance of Destroyable may not be reused between multiple try statements or multiple executions of the same try statement.

try (tx = Transaction()) {
    ...
}

• The resource is instantiated before the body of the try statement is executed, and
• destroy() is called when execution of the body of the try statement ends, even if an exception propagates out of the body of the try.