upgraded-complex-part-type

(upgraded-complex-part-type type &optional environment)

Returns the upgraded part type for a complex type specifier: a designator naming a subtype of real answers itself ('single-float stays 'single-float), while a compound real specifier answers its head's name ('(integer 0 10) answers integer). Anything else signals an error. The optional environment is evaluated and ignored. Works on all four backends.