The interface to C++ makes use of the following pragmas, which are primarily intended to be constructed automatically using a binding generator tool, although it is possible to construct them by hand.
Using these pragmas it is possible to achieve complete inter-operability between Ada tagged types and C++ class definitions. See Implementation Defined Pragmas, for more details.
Note: Pragma CPP_Class is currently obsolete. It is supported
for backward compatibility but its functionality is available
using pragma Import with Convention = CPP.
A few restrictions are placed on the use of the Access attribute in conjunction with subprograms subject to convention CPP: the attribute may be used neither on primitive operations of a tagged record type with convention CPP, imported or not, nor on subprograms imported with pragma CPP_Constructor.
In addition, C++ exceptions are propagated and can be handled in an
others choice of an exception handler. The corresponding Ada
occurrence has no message, and the simple name of the exception identity
Foreign_Exception. Finalization and awaiting dependent
tasks works properly when such foreign exceptions are propagated.
It is also possible to import a C++ exception using the following syntax:
LOCAL_NAME : exception; pragma Import (Cpp, [Entity =>] LOCAL_NAME, [External_Name =>] static_string_EXPRESSION);
The External_Name is the name of the C++ RTTI symbol. You can then cover a specific C++ exception in an exception handler.