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  1. OMG Issue

CPP13 — Concrete ValueType _init class problem

  • Key: CPP13-66
  • Legacy Issue Number: 6413
  • Status: open  
  • Source: AT&T ( Duncan Grisby)
  • Summary:

    The second-to-last paragraph of section says

    "For valuetypes that have no operations or initializers, a concrete type-specific factory class is generated whose implementation of the create_for_unmarshal function simply constructs an instance of the OBV_ class for the valuetype using new and the default constructor."

    As specified, that requires the generation of invalid C++. The OBV_ class is abstract since it does not have implementations of the ValueBase reference counting functions.

    Perhaps the intention is that the OBV_ classes in such cases should derive from DefaultValueRefCountBase. However, the wording and explanation in section 1.17.6 explicitly forbids this:

    "Note that it is the application-supplied concrete valuetype classes that must derive from these mix-in classes, not the valuetype classes generated by the IDL compiler."

    One solution that avoids the problem, and avoids restricting the application's use of the OBV_ classes is to generate yet another class that derives from both the OBV_ class and DefaultValueRefCountBase, for instantiation by the _init class's create_for_unmarshal function.

  • Reported: CPP 1.1 — Mon, 3 Nov 2003 05:00 GMT
  • Updated: Fri, 6 Mar 2015 20:58 GMT