From: Rusty Russell <rusty@rustcorp.com.au>
Date: Thu, 29 Mar 2012 04:28:33 +0000 (+1030)
Subject: cast: make sure suncc sees a constant.
X-Git-Url: http://git.ozlabs.org/?a=commitdiff_plain;h=74859ab18b10aaf990848e49d7789ff5c6cf96c6;hp=74859ab18b10aaf990848e49d7789ff5c6cf96c6;p=ccan

cast: make sure suncc sees a constant.

cast_const() et. al. are supposed to be a constant expression, so you can do things like:
	static char *p = cast_const(char *, (const char *)"hello");

Unfortunately, a cast to intptr_t and arithmetic makes suncc reject it as
a constant expression.  We need the cast, because (1) the expression could be
a void *, so we can't just add to it, and (2) gcc complains with -Wcast-qual
without it.

So instead of adding BUILD_BUG_OR_ZERO, we use a ? :, which keeps everyone happy.
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