From: Alejandro Colomar <colomar.6.4.3@gmail.com>
To: mtk.manpages@gmail.com, eggert@cs.ucla.edu, David.Laight@ACULAB.COM
Cc: Alejandro Colomar <colomar.6.4.3@gmail.com>,
linux-man@vger.kernel.org, gcc-patches@gcc.gnu.org,
libc-alpha@sourceware.org, linux-kernel@vger.kernel.org
Subject: [PATCH 2/2] system_data_types.7: void *: Add info about pointer artihmetic
Date: Fri, 2 Oct 2020 11:44:52 +0200 [thread overview]
Message-ID: <20201002094451.17997-1-colomar.6.4.3@gmail.com> (raw)
Reported-by: Paul Eggert <eggert@cs.ucla.edu>
Reported-by: David Laight <David.Laight@ACULAB.COM>
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
---
Paul and David,
Thanks for your input!
Alex
man7/system_data_types.7 | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/man7/system_data_types.7 b/man7/system_data_types.7
index 6451782db..bc7d5a8a0 100644
--- a/man7/system_data_types.7
+++ b/man7/system_data_types.7
@@ -1918,6 +1918,17 @@ A value of this type can't be dereferenced,
as it would give a value of type
.I void
which is not possible.
+Likewise, pointer arithmetic is not possible with this type.
+However, in GNU C, poitner arithmetic is allowed
+as an extension to the standard;
+this is done by treating the size of a
+.I void
+or of a function as 1.
+A consequence of this is that
+.I sizeof
+is also allowed on
+.I void
+and on function types, and returns 1.
.PP
The conversion specifier for
.I void *
--
2.28.0
next reply other threads:[~2020-10-02 9:45 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-02 9:44 Alejandro Colomar [this message]
2020-10-02 9:46 ` [PATCH 2/2] system_data_types.7: void *: Add info about pointer artihmetic Alejandro Colomar
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