LiteralValue = "{" [ ElementList [ "," ] ] "}" .
ElementList  = KeyedElement { "," KeyedElement } .
KeyedElement = [ Key ":" ] Element .
Key          = FieldName | Expression | LiteralValue .
FieldName    = identifier .
Element      = Expression | LiteralValue .
</pre>

<p>
Unless the LiteralType is a type parameter,
its <a href="#Underlying_types">underlying type</a>