[PATCH v2 1/2] system_data_types.7: Add 'void *'

[Alejandro Colomar <colomar.6.4.3@gmail.com>]

Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
---
 man7/system_data_types.7 | 47 ++++++++++++++++++++++++++++++++++++++--
 1 file changed, 45 insertions(+), 2 deletions(-)

diff --git a/man7/system_data_types.7 b/man7/system_data_types.7
index e42cf2557..e545aa1a0 100644
--- a/man7/system_data_types.7
+++ b/man7/system_data_types.7
@@ -679,7 +679,6 @@ See also the
 .I uintptr_t
 and
 .I void *
-.\" TODO: Document void *
 types in this page.
 .RE
 .\"------------------------------------- lconv ------------------------/
@@ -1781,7 +1780,6 @@ See also the
 .I intptr_t
 and
 .I void *
-.\" TODO: Document void *
 types in this page.
 .RE
 .\"------------------------------------- va_list ----------------------/
@@ -1815,6 +1813,51 @@ See also:
 .BR va_copy (3),
 .BR va_end (3)
 .RE
+.\"------------------------------------- void * -----------------------/
+.TP
+.I void *
+.RS
+According to the C language standard,
+a pointer to any object type may be converted to a pointer to
+.I void
+and back.
+POSIX further requires that any pointer,
+including pointers to functions,
+may be converted to a pointer to
+.I void
+and back.
+.PP
+Conversions from and to any other pointer type are done implicitly,
+not requiring casts at all.
+.PP
+A value of this type can't be dereferenced,
+as it would give a value of type
+.I void
+which is not possible.
+.PP
+The conversion specifier for
+.I void *
+for the
+.BR printf (3)
+and the
+.BR scanf (3)
+families of functions is
+.BR p ;
+resulting commonly in
+.B %p
+for printing
+.I void *
+values.
+.PP
+Conforming to:
+C99 and later; POSIX.1-2001 and later.
+.PP
+See also the
+.I intptr_t
+and
+.I uintptr_t
+types in this page.
+.RE
 .\"--------------------------------------------------------------------/
 .SH NOTES
 The structures described in this manual page shall contain,
-- 
2.28.0