On 07/10/19 14:56 -0400, Jason Merrill wrote:
On 10/7/19 1:42 PM, Marek Polacek wrote:
@@ -7401,8 +7432,20 @@ convert_like_real (conversion *convs, tree expr, tree
fn, int argnum,
error_at (loc, "cannot bind non-const lvalue reference of "
"type %qH to an rvalue of type %qI", totype, extype);
else if (!reference_compatible_p (TREE_TYPE (totype), extype))
- error_at (loc, "binding reference of type %qH to %qI "
- "discards qualifiers", totype, extype);
+ {
+ /* If we're converting from T[] to T[N], don't talk
+ about discarding qualifiers. (Converting from T[N] to
+ T[] is allowed by P0388R4.) */
+ if (TREE_CODE (extype) == ARRAY_TYPE
+ && TYPE_DOMAIN (extype) == NULL_TREE
+ && TREE_CODE (TREE_TYPE (totype)) == ARRAY_TYPE
+ && TYPE_DOMAIN (TREE_TYPE (totype)) != NULL_TREE)
+ error_at (loc, "binding reference of type %qH to %qI "
+ "discards array bounds", totype, extype);
If we're converting to T[N], that would be adding, not discarding,
array bounds?
I don't think the diagnostic would be very good if we say "adds array
bounds" though. How about being consistent with the existing error for
similar cases?
a.cc:4:17: error: invalid initialization of reference of type ‘int (&)[3]’ from
expression of type ‘int []’
int (&b)[3] = a;
^
