C++, "canceling a construction"

Hi /prog/

My is simple, but perhaps not so frequent.

How should I stop a construction of an object (c++)?

Basically I have a class with some data members which must fulfill some requirements. Say we initialize these data members upon construction, if the supplied values were erroneous then I guess I want to stop construction and throw an error. Is this the right idea? How do I "cancel the construction"?

Help much appreciated :)

>>1
Too little info. Where does the data for the object come from?

If you expect the data for the object to be bad from time to time (like when it's coming directly from user input), then I'd wager wrapping the construction in a builder class would be appropriate.

If you're thinking of doing assertions for debugging purposes  (checking pre- and post-conditions) then just throw an exception.