Returning reference to a local variable

Question

Why can this code run successfully in Code::block. The IDB just reports

warning: \"reference to local variable ‘tmp’ returned\",

Answer 1

The temporary object is deallocated, however its contents are still there on the stack, until something rewrites it. Try to call a few functions between calling your function and printing out the returned object:

const string& garbage = getString("Hello World!");
callSomeFunctionThatUsesALotOfStackMemory();
cout<< garbage << endl;