Why does the number of elements in a initializer list cause an ambiguous call error?

Question

Why are the first two calls to doSomething OK by the compiler, but using two elements in the list causes an ambiguous call?

#include 

        

Answer 1

"hello" and "stack" both decay to const char * which satisfies the InputIterator concept. This allow's them to match std::vector's constructor #4.

If you pass std::string objects the ambiguity is resolved.