1 // PR c++/89652
2 // { dg-do compile { target c++14 } }
3 // { dg-options "" }
4
foo(T & e)5 template <typename T> constexpr auto foo (T &e) { return e.foo (); }
bar(T & e)6 template <typename T> constexpr auto bar (T &e) { return foo (e); }
7 template <typename T, int N> struct A { typedef T a[N]; };
8 template <typename T, unsigned long N> struct B {
9 typedef T *b;
10 typename A<T, N>::a d;
fooB11 constexpr b foo () { return d; }
12 };
13 template <typename> struct C { long m; };
14 struct D { long n; };
15 template <typename, unsigned long> struct E {
16 B<C<int>, 1>::b p;
17 constexpr D operator* () { return {p->m}; }
18 constexpr E operator++ (int) { auto a{*this}; ++p; return a; }
19 };
20 template <typename T, unsigned long N>
21 constexpr bool operator!= (E<T, N> a, E<T, N>) { return a.p; }
22 template <unsigned long N, typename T, unsigned long M>
baz(B<T,M> s,B<D,N>)23 constexpr auto baz (B<T, M> s, B<D, N>)
24 {
25 B<D, M> t{};
26 auto q{foo (t)};
27 using u = E<T, M>;
28 auto v = u{bar (s)};
29 auto w = u{};
30 while (v != w)
31 *q++ = *v++;
32 return t;
33 }
34 constexpr auto a = B<C<int>, 5>{};
35 auto b = B<D, 0>{};
36 auto c = baz (a, b);
37