util: New BFS_FLEX_SIZEOF() macro for more precise flexible array allocations

See http://www.open-std.org/jtc1/sc22/wg14/www/docs/dr_282.htm for all
the fun behind this.

1 files changed, 1 insertions, 1 deletions

diff --git a/dstring.c b/dstring.c
index d370598..bfcf9bd 100644
--- a/dstring.c
+++ b/dstring.c
@@ -37,7 +37,7 @@ static struct dstring *dstrheader(const char *dstr) {
 
 /** Get the correct size for a dstring with the given capacity. */
 static size_t dstrsize(size_t capacity) {
-	return sizeof(struct dstring) + capacity + 1;
+	return BFS_FLEX_SIZEOF(struct dstring, data, capacity + 1);
 }
 
 /** Allocate a dstring with the given contents. */