ldb-test bytespec integer → generalized-boolean

bytespec — a byte specifier.

integer — an integer.

generalized-boolean — a generalized boolean.

Returns true if any of the bits of the byte in integer specified by bytespec is non-zero; otherwise returns false.

(ldb-test (byte 4 1) 16) → true 
(ldb-test (byte 3 1) 16) → false 
(ldb-test (byte 3 2) 16) → true

byte, ldb, zerop

(ldb-test bytespec n) ≡ 
(not (zerop (ldb bytespec n))) ≡ 
(logtest (ldb bytespec -1) n)