DDS-XTypes 1.3 RTF Avatar
  1. OMG Issue

DDSXTY13 — Restrictions on MAP key element type should include ENUM

  • Key: DDSXTY13-6
  • Status: closed  
  • Source: Airbus Group ( Mr. Oliver M. Kellogg)
  • Summary:

    DDS-XTypes 1.2 section (Collection Types) on page 30 bottom states:

    > * Element type: The concrete type to which all elements conform. (Collection Elements
    > that are of a subtype of the element type rather than the element type itself may be
    > truncated when they are serialized into a Data Representation.)
    > In the case of a map type, this attribute corresponds to the type of the value elements.
    > Map types have an additional attribute, the key element type, that indicates the type of the
    > may key objects.

    I believe there is a typo in "type of the may key objects" - drop the word "may" ?

    The paragraph continues:

    > Implementers of this specification need only support key elements of
    > signed and unsigned integer types and of narrow and wide string types; the behavior of
    > maps with other key element types is undefined and may not be portable.

    Is there a particular reason why enums were excluded from the supported key types?

  • Reported: DDS-XTypes 1.2b1 — Fri, 15 Sep 2017 13:51 GMT
  • Disposition: Closed; No Change — DDS-XTypes 1.3
  • Disposition Summary:

    Corrections were already applied in the formal document

    The typo mentioned in the description was already corrected in the formal DDS-XTYPES 1.2 document.

    Allowing enum to be used as key discriminator would introduce problems with type interoperability or data reception. Given that a similar behavior can be achieve at the application level (using the ordinal value associated with each enumeration literal) it seems better to leave the specification with the existing limitation.

  • Updated: Tue, 8 Oct 2019 17:55 GMT