10.2 Interfacing to C++

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. No suitable binding generator tool is supplied with GNAT though.

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.

pragma CPP_Class ([Entity =>] local_name)

The argument denotes an entity in the current declarative region that is declared as a tagged or untagged record type. It indicates that the type corresponds to an externally declared C++ class type, and is to be laid out the same way that C++ would lay out the type.

pragma CPP_Constructor ([Entity =>] local_name)

This pragma identifies an imported function (imported in the usual way with pragma Import) as corresponding to a C++ constructor.

pragma CPP_Vtable ...

One CPP_Vtable pragma can be present for each component of type CPP.Interfaces.Vtable_Ptr in a record to which pragma CPP_Class applies.