cl-all -p '(type-of #c(2.0 1))'            
 --> ABCL:       COMPLEX
 --> Allegro:    COMPLEX
 --> CCL:        (COMPLEX (SINGLE-FLOAT 1.0 2.0))

 --> CLisp:      COMPLEX

 --> CMUCL:      (COMPLEX (SINGLE-FLOAT 1.0 2.0))
 --> ECL:        COMPLEX
 --> MKCL:       COMPLEX
 --> SBCL:       (COMPLEX (SINGLE-FLOAT 1.0 2.0))