To: J3                                                     J3/19-175
From: Van Snyder
Subject: Concerning N2165
Date: 2019-July-05
References: N2165 04-192r1 04-357r1 18-154  18-156 18-274 19-167 19-168
            19-169 19-170

On 6 March 2019, Steve Lionel sent an e-mail message that began

  Attached is a draft of a paper listing all of the features that J3
  has  approved for being on the F202X request list. This ends up being
  the US  National Body list for WG5 consideration in Tokyo. Please look
  it over  and let me know of any omissions or errors....

I responded, remarking

  Is it too late to follow up on "Allowing a specification section in
  (some) constructs without forcing  use of BLOCK/END BLOCK seems
  useful. No paper. Defer discussion to next meeting." See 18-156.
  There was no further discussion.

This omission was not included in N2165.  Will there be further
discussion?

Concerning

  US22. Conditional expressions. Permits conditional evaluation of parts
        of the logical expression in an IF statement.  M217 paper 18-274
        contains extensive discussion and alternatives for syntax and
        semantics. Generally supported, but needs more work.

I responded

  Conditional expressions are NOT only for evaluating parts of
  expressions in IF statements.  They're for evaluating parts of ANY
  expression, anywhere, and calculating whether an actual argument is
  present. Calculating whether an actual argument is present was an
  important part of the 2004 proposal, and is an important part of the
  present proposal. When conditional expressions were rejected in 2004,
  in order to ameliorate the combinatorial-explosion problem with
  optional arguments, we got instead the kludge that unallocated or
  disassociated actual arguments corresponding to optional
  non-allocatable non-pointer dummy arguments are considered to be
  absent.  Not doing the right thing in the first place is a good way to
  make a mess.  Probably a permanent mess, since after we finally "do it
  the right way" we probably can't delete the kludge.

This error was not corrected in N2165.

See 04-192r1 and 04-357r1.

Concerning

  US24. Generics / templates / macros / containers for generic
        programming. (m217: 18-281r1, uc (templates)), and (m218: 18-154
        (macros)).

I responded

  Minutes of meeting 215 report that 18-112 (parameterized modules)
  should be part of the proposal for generic programming.

This error was not corrected in N2165.

Further, there was an explicit decision not to produce any particular
containers, such as lists, stacks, queues, trees....  Rather, support
should be provided to develop containers.

Containers are not an alternative to templates or macros or
parameterized modules.  Although templates or macros or parameterized
modules are useful to develop containers, they are not sufficient on
their own to provide adequate support to develop containers.  Containers
need additional support.  See 19-167, 19-168, 19-169 and 19-170.
Support for containers should be a separate work-item proposal.