anchor.diff:                                                      errcode-ret)))
             (is +cl-success+ (cl-retain-context context))))
         (subtest "clReleaseContext"
  -        (is +cl-invalid-context+ (cl-release-context (null-pointer)))
           (let ((context (cl-create-context-from-type properties
                                                       +cl-device-type-default+
                                                       (null-pointer)
  
positive.code:           (is +cl-invalid-device+ (cl-release-device (null-pointer))))))))
  
  (subtest "Context API"
    (with-foreign-objects ((platforms 'cl-platform-id)
                           (num-platforms 'cl-uint)
                           (devices 'cl-device-id)
  
negative.code:                                           devices
                                            num-devices))
        (subtest "clCreateContext"
          (setf (mem-aref errcode-ret 'cl-int) +cl-success+)
          (let ((context (cl-create-context (null-pointer)
                                            1
  