C++: Life span of temporary arguments?

Question

When creating a new instance of a MyClass as an argument to a function like so:

class MyClass
{
  MyClass(int a);
};    

myFunction(MyClass(42))         


        

Answer 1

The standard does indeed offer guarantees - from section 12.2/5:

A temporary bound to a reference parameter in a function call (5.2.2) persists until the completion of the full expression containing the call

However, in your code it is not clear if the parameter is being passed by reference or by value, though at some point a copy constructor which does take a reference will be used.