I would like to hear the theoretical explanation of what is happening here
#include <iostream>
int main(){
int ooh=0x0;
char *cc=0x0;
std::cout<<"hello!"<<cc<<"still"<<ooh<<"\n";
}
When running this we got
hello!
and the program finishes. I suppose it is because we are trying to print an address 0x0
I know it is wrong, but I would like to hear why is this wrong and what is happening under wraps
>Solution :
It has undefined behavior, because the specification of the operator<< overload for std::basic_ostream which is chosen here for <<cc has a precondition that the passed pointer is not a null pointer value and is instead pointing to a null-terminated byte string.
See e.g. https://en.cppreference.com/w/cpp/io/basic_ostream/operator_ltlt2:
The behavior is undefined if s is a null pointer.
of if you prefer to look in the standard draft itself, see [ostream.inserters.character]/3.
The line char *cc=0x0; initializes cc to a null pointer value.