Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.std.c > #1736

Re: Description of "." operator

Show all headers | View raw

In article <lntxrxnufa.fsf@nuthaus.mib.org>,
Keith Thompson  <kst-u@mib.org> wrote:
>N1570 6.5.2.3p3 says:
>
>    A postfix expression followed by the . operator and an identifier
>    designates a member of a structure or union object. The value
>    is that of the named member, and is an lvalue if the first
>    expression is an lvalue.
>
>Consider the use of the word "object" in the first sentence.
>
>An expression of struct type doesn't necessarily refer to an *object* of
>that type.  

Look up 'temporary lifetime' (6.2.4).

>For example:
>
>    struct pair { int x; int y; };
>    struct pair func(void) {
>        struct pair result = { 10, 20 };
>        return result;
>    }
>    ...
>    int y = func().y;

Change your code to:

    struct pair { int x; int y; char thisisbs[1]; };
    struct pair func(void) {
        struct pair result = { 10, 20 };
        return result;
    }
    ...
    int y = func().y;

to make it work.

Back to comp.std.c | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Description of "." operator Keith Thompson <kst-u@mib.org> - 2012-12-07 18:34 -0800
  Re: Description of "." operator Keith Thompson <kst-u@mib.org> - 2012-12-08 10:43 -0800
    Re: Description of "." operator Jens Gustedt <jens.gustedt@loria.fr> - 2012-12-10 00:35 +0100
      Re: Description of "." operator Keith Thompson <kst-u@mib.org> - 2012-12-09 20:02 -0800
  Re: Description of "." operator jgk@panix.com (Joe keane) - 2012-12-09 23:34 +0000
    Re: Description of "." operator Keith Thompson <kst-u@mib.org> - 2012-12-09 20:00 -0800
  Re: Description of "." operator Tim Rentsch <txr@alumni.caltech.edu> - 2012-12-20 23:32 -0800
    Re: Description of "." operator Keith Thompson <kst-u@mib.org> - 2012-12-21 02:08 -0800
      Re: Description of "." operator Eric Sosman <esosman@comcast-dot-net.invalid> - 2012-12-21 09:18 -0500
        Re: Description of "." operator Tim Rentsch <txr@alumni.caltech.edu> - 2012-12-21 08:45 -0800
      Re: Description of "." operator Tim Rentsch <txr@alumni.caltech.edu> - 2012-12-21 08:37 -0800
  Re: Description of "." operator Shao Miller <sha0.miller@gmail.com> - 2013-01-06 01:23 -0500
    Re: Description of "." operator Keith Thompson <kst-u@mib.org> - 2013-01-05 23:51 -0800
      Re: Description of "." operator Shao Miller <sha0.miller@gmail.com> - 2013-01-06 13:49 -0500
        Re: Description of "." operator Keith Thompson <kst-u@mib.org> - 2013-01-06 22:12 -0800
          Re: Description of "." operator Shao Miller <sha0.miller@gmail.com> - 2013-01-17 23:19 -0500
            Re: Description of "." operator Shao Miller <sha0.miller@gmail.com> - 2013-01-18 20:47 -0500
              Re: Description of "." operator Keith Thompson <kst-u@mib.org> - 2013-01-18 20:14 -0800
              Re: Description of "." operator jgk@panix.com (Joe keane) - 2013-01-20 20:07 +0000
                Re: Description of "." operator Shao Miller <sha0.miller@gmail.com> - 2013-01-20 15:36 -0500

csiph-web