catching exception objects by reference, temporaries, lifetime issues

Question

Consider the following code:

#include 
#include 

void foo()
{
    throw std::runtime_error(\"How long do I live?\");
}

int         


        

Answer 1

A thrown exception is not a temporary - the compiler-generated exception code keeps a permanent copy of it. So you can bind it to a non-const reference.

[edit] I just check the standard and it actually refers to a temporary copy. However, the lifetime of the temporary is guaranteed to be at least as long as that of the exception handler.