Paul Eggert wrote:
> * modules/flexmember, m4/flexmember.m4: New files.
Nice. Maybe add a reference to ISO C99 6.7.2.1.(16) ?
Also, a little bit of methodology explanation would be nice, for those
who would naively want to use sizeof on such a type.
*** gnulib-20061106/m4/flexmember.m4 2006-11-06 22:58:29.000000000 +0100
--- gnulib-20061106-modified/m4/flexmember.m4 2006-11-07 02:12:12.000000000
+0100
***************
*** 41,47 ****
[Define to nothing if C supports flexible array members, and to
1 if it does not. That way, with a declaration like `struct s
{ int n; double d@<:@FLEXIBLE_ARRAY_MEMBER@:>@; };', the struct hack
! can be used with pre-C99 compilers.])
else
AC_DEFINE([FLEXIBLE_ARRAY_MEMBER], 1)
fi
--- 41,51 ----
[Define to nothing if C supports flexible array members, and to
1 if it does not. That way, with a declaration like `struct s
{ int n; double d@<:@FLEXIBLE_ARRAY_MEMBER@:>@; };', the struct hack
! can be used with pre-C99 compilers.
! When computing the size of such an object, don't use 'sizeof (struct
s)'
! as it overestimates the size. Use 'offsetof (struct s, d)' instead.
! Don't use 'offsetof (struct s, d@<:@0@:>@)', as this doesn't work with
! MSVC and with C++ compilers.])
else
AC_DEFINE([FLEXIBLE_ARRAY_MEMBER], 1)
fi
