Why does storing references (not pointers) in containers in C++ not work?

Question

In my program I have a STL set.

set myStrings;

To improve the efficiency of my code I changed it to hold, only pointers. (I d

Answer 1

Not directly relevant to the "why", but to give an answer to the implied desire to do this, I would mention that the c++11 standard library has std::reference_wrapper to enable this. It is implicitly convertible to a reference and it is storable in standard containers.