On Wed, 19 Feb 2020 at 07:53, Klaus Doldinger
<klaus.doldinger64@xxxxxxxxx> wrote:
>
> The following was possible in v9:
>
> template<auto N>
> struct A {
> constexpr auto size() const {
> return N;
> }
> };
>
> template<typename A>
> void foo(const A& a) {
> constexpr auto s = a.size();
> }
>
> int main() {
> A<10> x1;
> foo(x1);
> }
>
> In v10 this is rejected.
>
> Looks like a bug?
No, I don't think so. The parameter a is not a constant expression, so
a.size() is not a constant expression, so can't be used to initialize
a constexpr variable.
