Specializing.
(values ↓value-typespec)
&allow-other-keys
]
typespec—a type specifier.
This type specifier can be used only as the value-type in a
function
type specifier or a the
special form. It is used to specify individual types
when multiple values are involved.
The &optional
and &rest
markers can appear in the value-type list;
they indicate the parameter list of a function that,
when given to multiple-value-call
along with the values,
would correctly receive those values.
The symbol * may not be among the value-types.
The symbol values is not valid as a type specifier;
and, specifically, it is not an abbreviation for (values)
.