CLCS
Function

array-element-type

array-element-type arraytypespec

Arguments and Values

arrayan array.
typespeca type specifier.

Description

Returns a type specifier which represents the actual array element type of the array, which is the set of objects that such an array can hold. (Because of array upgrading, this type specifier can in some cases denote a supertype of the expressed array element type of the array.)

Examples

 (array-element-type (make-array 4)) ⇒  T
 (array-element-type (make-array 12 :element-type '(unsigned-byte 8))) 
⇒  implementation-dependent
 (array-element-type (make-array 12 :element-type '(unsigned-byte 5)))
⇒  implementation-dependent

 (array-element-type (make-array 5 :element-type '(mod 5)))

could be (mod 5), (mod 8), fixnum, t, or any other type of which (mod 5) is a subtype.

Affected By

The implementation.

Exceptional Situations

Should signal an error of type type-error if its argument is not an array.