Why can we use the Indirection/Dereferencing (*) operator on a boost::optional<T> containing boost::none?

Question

The following lines will not throw an exception at run-time:

    boost::optional<double> dummy(boost::none);
    double testValue = *dummy;

Is there a reason why boost developers have decided to not throw when using the indirection operator (*) on a boost::optional containing boost::none ? For reference, I get random values in testValue in the code above as it is probably assigning random unitialised parts of memory.

This can lead to silent errors as you are responsible of checking the value before to use it.

Answer 1

I can think of 2:

• Consistency -- basic types don't check this.
• Speed. Dereferencing is a small and fast operation so adding a check can incur a lot of overhead, proportionally.

It is the same case as for array bounds checking: nice to have, but expensive.