GPRBUILD and multiple file suffix (.cc, .cpp)

Question

The GNAT Project files (.gpr) allow to specify the suffix of source code for compilation. For example:

package Naming is
    for Spec_Suffix ("c++") use ".h";
    for Body_Suffix ("c++") use ".cc";
 end Naming;

However in some cases, like C++ you may need to support multiple suffixes when code comes from several sources (typically .cc and .cpp).

Any idea how to do this?