Migrating from HP C++ (cfront) to HP aC++

The overload resolution for operators has been updated to reflect the C++ standard. You may see some additional "ambiguous" function error messages displayed.

Most frequently reported migration issue: enum x { x1, }; The trailing comma is an error, and aC++ generates Warning 921.

Changes to temporary creation for rvalues used to initialize return values which are const references now causes:

Error 652: Exact position unknown; near file, line#.
Initialization of the result <some const &> requires creating a
temporary, yet the temporary's lifetime ends with the return from the function.

You can bracket your HP aC++ changes with the macro defined by the draft standard. For example:

#if __cplusplus >= 199707L
// HP aC++ Code
#endif // __cplusplus >= 199707L

If you are using directed mode instantiation with the cfront based compiler, an awk script can be used to convert your file to an instantiation file that uses the explicit instantiation syntax. Note that explicit instantiation syntax can be used to instantiate a template and all of its member functions, an individual template function, or a template class's member function. The HP aC++ Online Programmer's Guide contains an example script.

In a template, a name with a parameter-dependent qualifier is not taken to be a type unless it is explicitly declared as one with the typename keyword.

You need to explicitly declare a type or a member function type using the typename keyword when all of the following are true:

For example, the following code includes the typename keyword to declare iterator as a type:

#include <list>											
template <class Element>
class Foo {
public:
   list<Element> e;
   typedef typename list<Element>::iterator MyIterator;
};

For more information, refer to the HP aC++ Transition Guide at the following World Wide Web URL:

http://www.hp.com/esy/lang/cpp/tguide