Hi,
On 09/02/2014 05:45 PM, Jason Merrill wrote:
On 09/02/2014 11:07 AM, Paolo Carlini wrote:
Anyway, what about the below? Certainly works for the tests which we
have got.
Hmm. This is definitely an improvement, as it allows a subset of
a non-volatile glvalue of literal type that refers to a non-volatile
object whose lifetime began within the evalution of e
But it doesn't cover all of that, and in any case we shouldn't need to
explicitly handle that just for types with mutable subobjects.
I think perhaps it would be better to remove that hunk as in your
initial patch and replace it with a check in constant_value_1 and an
explanation in non_const_var_error.
In practice, I'm encountering a rather serious problem with moving away
the check, I'm looking more into it, but maybe I can already explain it
to you...
The issue, AFAICS, boils down to the difference itself between
cxx_eval_outermost_constant_expr and cxx_eval_constant_expression:
changing constant_value_1 means that in principle all the calls of the
latter (for VAR_DECLs) are impacted. Thus, for example, for the call at
the beginning of cxx_eval_component_reference:
struct A
{
int i;
mutable int j;
};
constexpr A a = { 0, 1 };
constexpr int i = a.i;
how do we avoid emitting a wrong error for the a of a.i?
Paolo.
