Re: The C Containers Library

From	Tim Rentsch <txr@alumni.caltech.edu>
Newsgroups	comp.lang.c
Subject	Re: The C Containers Library
Date	2012-09-07 17:31 -0700
Organization	A noiseless patient Spider
Message-ID	<kfnehmdfj91.fsf@x-alumni2.alumni.caltech.edu> (permalink)
References	(9 earlier) <jvqmsl$a4i$1@speranza.aioe.org> <jvr5a4$f9l$1@speranza.aioe.org> <0.6b37705966472232f93d.20120807153556BST.87lihqzs4z.fsf@bsb.me.uk> <kfnoblhhbaa.fsf@x-alumni2.alumni.caltech.edu> <0.2d2872b78904cdb82b49.20120908000729BST.87sjatph3i.fsf@bsb.me.uk>

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Ben Bacarisse <ben.usenet@bsb.me.uk> writes:

> Tim Rentsch <txr@alumni.caltech.edu> writes:
>
>> Ben Bacarisse <ben.usenet@bsb.me.uk> writes:
>>
>>> C++'s lambdas are not closures (I am sure you know this) so
>>> they don't add any new concepts.
>>
>> Forgive my ignorance - how are lambdas different from closures?
>> I know a lot about closures, but only a little about C++ lambdas.
>
> Then I'm sure the difference is just one of interpreting the term.
>
> The main point, for me, is that C++ lambdas are not simply a piece of
> code that can refer to the environment being "closed over".  They don't
> treat the environment in a uniform way as a closure would.  For example:
>
>   struct S { int i; };
>   enum { name = 42; };
>   int i;
>   auto l = []{ S s = {name}; };
>
> The lambda body can refer to 'S' and 'name' (and, incidentally, all
> 'global' names like functions and file-scope object names) but it can't
> refer to 'i' unless we specify either a default or an explicit capture
> mode (by reference or by copy).
>
> C++'s "capture by copying" is very useful, but it's not at all what a
> "plain" closure does (thought you can get the same effect easily enough
> using closures).  Capture by reference is very close, except for two
> things: the non-uniform treatment of the environment I've already
> mentioned,

This part is what I'm confused about.  If there's a default
by-reference capture mode, how is the treatment of the
environment non-uniform?  My assumption is that giving
a default capture mode of reference affects all variables
in the outer environment the same way (obviously types and
enum's are different, but that doesn't matter since they
can't change).

> and the fact that the capture has no effect on the lifetime
> of the object referenced.  [snip elaboration]

I get that, this difference is the one I was expecting,
and was wondering what other differences there might be.

Thread

The C Containers Library jacob navia <jacob@spamsink.net> - 2012-07-08 21:53 +0200
  Re: The C Containers Library aftnix <aftnix@gmail.com> - 2012-07-26 13:13 -0700
    Re: The C Containers Library jacob navia <jacob@spamsink.net> - 2012-07-26 22:31 +0200
      Re: The C Containers Library lawrence.jones@siemens.com - 2012-07-28 17:46 -0400
        Re: The C Containers Library jacob navia <jacob@spamsink.net> - 2012-07-29 02:05 +0200
          Re: The C Containers Library lawrence.jones@siemens.com - 2012-07-30 14:48 -0400
          Re: The C Containers Library Phil Bradby <nospam@nospam.com> - 2012-08-01 21:00 +0000
            Re: The C Containers Library jacob navia <jacob@spamsink.net> - 2012-08-01 23:18 +0200
            Re: The C Containers Library Nick Keighley <nick_keighley_nospam@hotmail.com> - 2012-08-02 00:48 -0700
              Re: The C Containers Library James Kuyper <jameskuyper@verizon.net> - 2012-08-02 07:00 -0400
                Re: The C Containers Library jacob navia <jacob@spamsink.net> - 2012-08-02 13:27 +0200
                Re: The C Containers Library Quentin Pope <qp19433@hotmail.NOSPAM.com> - 2012-08-02 20:27 +0000
                Re: The C Containers Library Nick Keighley <nick_keighley_nospam@hotmail.com> - 2012-08-02 05:13 -0700
                Re: The C Containers Library Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-08-02 14:26 -0700
                Re: The C Containers Library Kenneth Brody <kenbrody@spamcop.net> - 2012-08-03 10:47 -0400
        Re: The C Containers Library Noob <root@localhost> - 2012-07-29 09:58 +0200
          Re: The C Containers Library "Ansel" <tinker454@trytospammenowloser.com> - 2012-07-30 00:31 -0600
            Re: The C Containers Library Noob <root@localhost> - 2012-07-30 09:45 +0200
              Re: The C Containers Library Nick Keighley <nick_keighley_nospam@hotmail.com> - 2012-07-30 02:10 -0700
          Re: The C Containers Library lawrence.jones@siemens.com - 2012-07-30 14:54 -0400
    Re: The C Containers Library James Kuyper <jameskuyper@verizon.net> - 2012-07-26 16:52 -0400
      Re: The C Containers Library jacob navia <jacob@spamsink.net> - 2012-07-26 22:56 +0200
        Re: The C Containers Library pacman@kosh.dhis.org (Alan Curry) - 2012-07-26 22:29 +0000
          Re: The C Containers Library jacob navia <jacob@spamsink.net> - 2012-07-27 01:50 +0200
            Re: The C Containers Library pacman@kosh.dhis.org (Alan Curry) - 2012-07-27 22:28 +0000
          Re: The C Containers Library Nick Keighley <nick_keighley_nospam@hotmail.com> - 2012-07-29 06:31 -0700
            Re: The C Containers Library "Ansel" <tinker454@trytospammenowloser.com> - 2012-07-30 00:26 -0600
              Re: The C Containers Library Nick Keighley <nick_keighley_nospam@hotmail.com> - 2012-07-30 02:21 -0700
                Re: The C Containers Library "Ansel" <tinker454@trytospammenowloser.com> - 2012-08-02 02:27 -0600
                Re: The C Containers Library Rui Maciel <rui.maciel@gmail.com> - 2012-08-02 16:43 +0100
                Re: The C Containers Library Ansel <lateknightdev@gmail.com> - 2012-08-02 17:07 -0700
                Re: The C Containers Library Rui Maciel <rui.maciel@gmail.com> - 2012-08-03 22:21 +0100
                Re: The C Containers Library Ansel <lateknightdev@gmail.com> - 2012-08-03 15:43 -0700
                Re: The C Containers Library Anders Wegge Keller <wegge@wegge.dk> - 2012-08-04 06:32 +0200
                Re: The C Containers Library Nick Keighley <nick_keighley_nospam@hotmail.com> - 2012-08-04 01:52 -0700
                Re: The C Containers Library "Ansel" <tinker454@trytospammenowloser.com> - 2012-08-04 22:36 -0600
                Re: The C Containers Library Anders Wegge Keller <wegge@wegge.dk> - 2012-08-05 08:36 +0200
                Re: The C Containers Library "Ansel" <tinker454@trytospammenowloser.com> - 2012-08-05 01:28 -0600
                Re: The C Containers Library Anders Wegge Keller <wegge@wegge.dk> - 2012-08-05 11:31 +0200
                Re: The C Containers Library "Ansel" <tinker454@trytospammenowloser.com> - 2012-08-05 03:48 -0600
            Re: The C Containers Library Nick Keighley <nick_keighley_nospam@hotmail.com> - 2012-08-04 03:41 -0700
        Re: The C Containers Library jacob navia <jacob@spamsink.net> - 2012-07-27 01:55 +0200
  Re: The C Containers Library wkaras@yahoo.com - 2012-07-26 13:45 -0700
    Re: The C Containers Library jacob navia <jacob@spamsink.net> - 2012-07-26 22:53 +0200
      Re: The C Containers Library wkaras@yahoo.com - 2012-07-26 18:46 -0700
        Re: The C Containers Library jacob navia <jacob@spamsink.net> - 2012-07-27 10:59 +0200
          Re: The C Containers Library gwowen <gwowen@gmail.com> - 2012-07-27 03:39 -0700
          Re: The C Containers Library wkaras@yahoo.com - 2012-07-27 11:34 -0700
        Re: The C Containers Library jacob navia <jacob@spamsink.net> - 2012-07-27 11:04 +0200
          Re: The C Containers Library W Karas <wkaras@yahoo.com> - 2012-07-27 13:10 -0700
  Re: The C Containers Library wkaras@yahoo.com - 2012-07-26 18:54 -0700
    Re: The C Containers Library James Kuyper <jameskuyper@verizon.net> - 2012-07-27 10:25 -0400
      Re: The C Containers Library wkaras@yahoo.com - 2012-07-27 11:28 -0700
        Re: The C Containers Library James Kuyper <jameskuyper@verizon.net> - 2012-07-27 15:17 -0400
          Re: The C Containers Library wkaras@yahoo.com - 2012-07-27 13:00 -0700
          Re: The C Containers Library jacob navia <jacob@spamsink.net> - 2012-07-29 02:02 +0200
            Re: The C Containers Library "Ansel" <tinker454@trytospammenowloser.com> - 2012-07-28 22:08 -0600
              Re: The C Containers Library jacob navia <jacob@spamsink.net> - 2012-07-29 08:46 +0200
                Re: The C Containers Library pacman@kosh.dhis.org (Alan Curry) - 2012-07-29 07:43 +0000
                Re: The C Containers Library jacob navia <jacob@spamsink.net> - 2012-07-29 09:59 +0200
                Re: The C Containers Library Nick Keighley <nick_keighley_nospam@hotmail.com> - 2012-07-29 06:43 -0700
                Re: The C Containers Library pacman@kosh.dhis.org (Alan Curry) - 2012-07-29 17:27 +0000
                Re: The C Containers Library jacob navia <jacob@spamsink.net> - 2012-07-29 20:56 +0200
                Re: The C Containers Library pacman@kosh.dhis.org (Alan Curry) - 2012-07-30 00:07 +0000
                Re: The C Containers Library "Ansel" <tinker454@trytospammenowloser.com> - 2012-07-30 00:07 -0600
                Re: The C Containers Library Keith Thompson <kst-u@mib.org> - 2012-07-29 11:58 -0700
                Re: The C Containers Library jacob navia <jacob@spamsink.net> - 2012-07-29 22:06 +0200
                Re: The C Containers Library jacob navia <jacob@spamsink.net> - 2012-07-29 22:23 +0200
                Re: The C Containers Library Melzzzzz <mel@zzzzz.invalid> - 2012-07-30 00:13 +0200
                Re: The C Containers Library "Ansel" <tinker454@trytospammenowloser.com> - 2012-07-30 00:13 -0600
                Re: The C Containers Library Keith Thompson <kst-u@mib.org> - 2012-07-30 01:10 -0700
                Re: The C Containers Library "Ansel" <tinker454@trytospammenowloser.com> - 2012-07-30 02:57 -0600
                Re: The C Containers Library Jorgen Grahn <grahn+nntp@snipabacken.se> - 2012-07-30 15:47 +0000
                Re: The C Containers Library Keith Thompson <kst-u@mib.org> - 2012-07-30 13:01 -0700
                Re: The C Containers Library Nick Keighley <nick_keighley_nospam@hotmail.com> - 2012-07-30 04:53 -0700
                Re: The C Containers Library Keith Thompson <kst-u@mib.org> - 2012-07-30 13:04 -0700
                Re: The C Containers Library "Ansel" <tinker454@trytospammenowloser.com> - 2012-08-02 02:11 -0600
                Re: The C Containers Library James Kuyper <jameskuyper@verizon.net> - 2012-08-02 06:52 -0400
                Re: The C Containers Library James Kuyper <jameskuyper@verizon.net> - 2012-08-02 06:46 -0400
                Re: The C Containers Library Rui Maciel <rui.maciel@gmail.com> - 2012-07-30 00:41 +0100
                Re: The C Containers Library jacob navia <jacob@spamsink.net> - 2012-07-30 09:45 +0200
                Re: The C Containers Library "Ansel" <tinker454@trytospammenowloser.com> - 2012-07-29 23:05 -0600
                Re: The C Containers Library "Ansel" <tinker454@trytospammenowloser.com> - 2012-07-29 22:52 -0600
                Re: The C Containers Library Nick Keighley <nick_keighley_nospam@hotmail.com> - 2012-07-30 04:56 -0700
                Re: The C Containers Library "Ansel" <tinker454@trytospammenowloser.com> - 2012-08-02 02:07 -0600
                Re: The C Containers Library jacob navia <jacob@spamsink.net> - 2012-07-30 17:49 +0200
        Re: The C Containers Library Rui Maciel <rui.maciel@gmail.com> - 2012-07-28 09:17 +0100
          Re: The C Containers Library W Karas <wkaras@yahoo.com> - 2012-07-28 15:17 -0700
            Re: The C Containers Library Rui Maciel <rui.maciel@gmail.com> - 2012-07-29 11:10 +0100
        Re: The C Containers Library Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-07-28 06:51 -0700
          Re: The C Containers Library Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-07-28 17:23 +0100
            Re: The C Containers Library Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-07-30 13:40 -0700
              Re: The C Containers Library Melzzzzz <mel@zzzzz.invalid> - 2012-07-31 00:24 +0200
          Re: The C Containers Library Melzzzzz <mel@zzzzz.invalid> - 2012-07-31 00:05 +0200
          Re: The C Containers Library Rui Maciel <rui.maciel@gmail.com> - 2012-07-31 00:53 +0100
            Re: The C Containers Library jacob navia <jacob@spamsink.net> - 2012-07-31 09:24 +0200
            Re: The C Containers Library Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-08-02 14:45 -0700
              Re: The C Containers Library Rui Maciel <rui.maciel@gmail.com> - 2012-08-03 22:31 +0100
                Re: The C Containers Library jacob navia <jacob@spamsink.net> - 2012-08-04 00:01 +0200
                Re: The C Containers Library Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-08-03 23:45 +0100
                Re: The C Containers Library "Ansel" <tinker454@trytospammenowloser.com> - 2012-08-04 22:47 -0600
                Re: The C Containers Library "Ansel" <tinker454@trytospammenowloser.com> - 2012-08-04 22:41 -0600
                Re: The C Containers Library Rui Maciel <rui.maciel@gmail.com> - 2012-08-07 10:24 +0100
                Re: The C Containers Library jacob navia <jacob@spamsink.net> - 2012-08-07 15:30 +0200
                Re: The C Containers Library Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-08-07 15:35 +0100
                Re: The C Containers Library Tim Rentsch <txr@alumni.caltech.edu> - 2012-09-07 12:40 -0700
                Re: The C Containers Library Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-09-08 00:07 +0100
                Re: The C Containers Library Tim Rentsch <txr@alumni.caltech.edu> - 2012-09-07 17:31 -0700
                Re: The C Containers Library Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-09-08 03:14 +0100
                Re: The C Containers Library Tim Rentsch <txr@alumni.caltech.edu> - 2012-09-08 05:22 -0700
                Re: The C Containers Library Tim Rentsch <txr@alumni.caltech.edu> - 2012-09-07 12:36 -0700
                Re: The C Containers Library Nick Keighley <nick_keighley_nospam@hotmail.com> - 2012-08-08 02:26 -0700
                Re: The C Containers Library jacob navia <jacob@spamsink.net> - 2012-08-08 17:25 +0200
            Re: The C Containers Library 88888 Dihedral <dihedral88888@googlemail.com> - 2012-08-03 16:04 -0700
  Re: The C Containers Library SG <s.gesemann@gmail.com> - 2012-08-04 04:52 -0700
    Re: The C Containers Library jacob navia <jacob@spamsink.net> - 2012-08-04 18:42 +0200
      Re: The C Containers Library Ike Naar <ike@faeroes.freeshell.org> - 2012-08-04 19:17 +0000
        Re: The C Containers Library Ike Naar <ike@faeroes.freeshell.org> - 2012-08-04 19:22 +0000
        Re: The C Containers Library jacob navia <jacob@spamsink.net> - 2012-08-04 22:14 +0200
        Re: The C Containers Library jacob navia <jacob@spamsink.net> - 2012-08-05 00:15 +0200
          Re: The C Containers Library Ike Naar <ike@faeroes.freeshell.org> - 2012-08-04 23:13 +0000
            Re: The C Containers Library "Ansel" <tinker454@trytospammenowloser.com> - 2012-08-04 22:53 -0600

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