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Groups > comp.lang.c++ > #87431
| From | Ben Bacarisse <ben.usenet@bsb.me.uk> |
|---|---|
| Newsgroups | comp.lang.c++ |
| Subject | Re: What is a `**ppEnum`? |
| Date | 2022-11-17 13:03 +0000 |
| Organization | A noiseless patient Spider |
| Message-ID | <87v8ndu41f.fsf@bsb.me.uk> (permalink) |
| References | (2 earlier) <tkt2u9$1no3l$2@dont-email.me> <ff8b48f4-e2f9-4ae9-865d-7e657f4ac1c0n@googlegroups.com> <tkt73c$1o60i$2@dont-email.me> <tl2bj1$1en4$1@gioia.aioe.org> <tl3t9g$2f98u$1@dont-email.me> |
T <T@invalid.invalid> writes:
> The only thing I am not following, is how do I know the
> length of each item in the array and how many items are
> in the array.
I typed this up before seeing Mike's reply. It seems this has been
covered more than once, but since I've typed it already...
Do you understand the concept of using a pointer to "return" a value
from a function? For example
int get_some_fancy_hardware_value(long *res);
This interface return success (0) or some negative value indicating an
error so the return value can't be used to get the fancy value out of the
hardware. Instead, it's placed in the long pointed to by the long *
argument. You'd write:
long hw_val;
if (get_some_fancy_hardware_value(&hw_val) >= 0)
printf("value=%ld\n", hw_val);
else fprintf(stderr, "Could not get hardware value.\n");
Sometimes the value you want to get out is itself a pointer. In these
cases that argument will be a pointer to a pointer, as in your example.
--
Ben.
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What is a `**ppEnum`? T <T@invalid.invalid> - 2022-11-14 00:39 -0800
Re: What is a `**ppEnum`? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-11-14 01:29 -0800
Re: What is a `**ppEnum`? T <T@invalid.invalid> - 2022-11-14 01:46 -0800
Re: What is a `**ppEnum`? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-11-14 01:52 -0800
Re: What is a `**ppEnum`? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-11-14 01:55 -0800
Re: What is a `**ppEnum`? Öö Tiib <ootiib@hot.ee> - 2022-11-14 02:30 -0800
Re: What is a `**ppEnum`? T <T@invalid.invalid> - 2022-11-14 02:38 -0800
Re: What is a `**ppEnum`? Öö Tiib <ootiib@hot.ee> - 2022-11-14 02:48 -0800
Re: What is a `**ppEnum`? Öö Tiib <ootiib@hot.ee> - 2022-11-14 01:39 -0800
Re: What is a `**ppEnum`? T <T@invalid.invalid> - 2022-11-14 01:48 -0800
Re: What is a `**ppEnum`? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-11-14 02:01 -0800
Re: What is a `**ppEnum`? Öö Tiib <ootiib@hot.ee> - 2022-11-14 02:33 -0800
Re: What is a `**ppEnum`? T <T@invalid.invalid> - 2022-11-14 02:59 -0800
Re: What is a `**ppEnum`? Öö Tiib <ootiib@hot.ee> - 2022-11-14 03:33 -0800
Re: What is a `**ppEnum`? T <T@invalid.invalid> - 2022-11-14 11:10 -0800
Re: What is a `**ppEnum`? Juha Nieminen <nospam@thanks.invalid> - 2022-11-16 09:47 +0000
Re: What is a `**ppEnum`? T <T@invalid.invalid> - 2022-11-16 15:55 -0800
Re: What is a `**ppEnum`? scott@slp53.sl.home (Scott Lurndal) - 2022-11-17 00:19 +0000
Re: What is a `**ppEnum`? Mike Terry <news.dead.person.stones@darjeeling.plus.com> - 2022-11-17 01:21 +0000
Re: What is a `**ppEnum`? T <T@invalid.invalid> - 2022-11-16 18:01 -0800
Re: What is a `**ppEnum`? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-11-16 18:40 -0800
Re: What is a `**ppEnum`? Mike Terry <news.dead.person.stones@darjeeling.plus.com> - 2022-11-17 04:18 +0000
Re: What is a `**ppEnum`? Juha Nieminen <nospam@thanks.invalid> - 2022-11-17 08:25 +0000
Re: What is a `**ppEnum`? T <T@invalid.invalid> - 2022-11-17 00:31 -0800
Re: What is a `**ppEnum`? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-11-17 10:17 -0800
Re: What is a `**ppEnum`? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2022-11-17 13:03 +0000
Re: What is a `**ppEnum`? T <T@invalid.invalid> - 2022-11-17 10:28 -0800
Re: What is a `**ppEnum`? Mike Terry <news.dead.person.stones@darjeeling.plus.com> - 2022-11-17 03:36 +0000
Re: What is a `**ppEnum`? T <T@invalid.invalid> - 2022-11-16 20:57 -0800
Re: What is a `**ppEnum`? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-11-14 14:34 +0100
Re: What is a `**ppEnum`? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-11-14 14:44 +0100
Re: What is a `**ppEnum`? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-11-14 09:12 -0800
Re: What is a `**ppEnum`? T <T@invalid.invalid> - 2022-11-14 11:02 -0800
Re: What is a `**ppEnum`? Ralf Fassel <ralfixx@gmx.de> - 2022-11-15 10:17 +0100
Re: What is a `**ppEnum`? Öö Tiib <ootiib@hot.ee> - 2022-11-15 04:24 -0800
Re: What is a `**ppEnum`? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-11-15 14:04 +0100
Re: What is a `**ppEnum`? T <T@invalid.invalid> - 2022-11-15 08:28 -0800
Re: What is a `**ppEnum`? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-11-17 16:21 +0100
Re: What is a `**ppEnum`? T <T@invalid.invalid> - 2022-11-17 16:39 -0800
Re: What is a `**ppEnum`? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-11-19 14:16 +0100
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