[dan00]

My bad, I thought std::optional is part of C++14, it seems to be part of the next standard C++17, but there's still boost::optional.

About the container issue: if you have objects that might fail during the creation it seems like a bad idea to allow things like:

    std::vector<Foo> foos(10);

Having a separate initialization method which might fail - like proposed by others - is another option, but this means your objects need some kind of internal initialization state, and whenever you're handling such an object you never can be absolute sure that it's in a valid state.

I'm quite a big fan of making invalid state not representable in an object and handling failure cases as early as possible.

What the create method returns depends heavily on your use case. If the returned objects can always be allocated on the heap, then a pointer or unique_ptr can be returned.