1 // PR c++/53349
2 // { dg-do compile { target c++11 } }
3 
4 template <int N>
5 struct Foo {
FooFoo6   constexpr Foo(const Foo<N-1> a) : m_a(a)     {}
FooFoo7   constexpr Foo(const Foo<N> &a)  : m_a(a.m_a) {}
8 
9   Foo<N-1> m_a;
10 };
11 
12 template <> struct Foo<0> {};
13 
14 constexpr Foo<1> catty1(Foo<1> x) { return x; }
15 constexpr Foo<2> catty2(Foo<1> x) { return Foo<2>(catty1(x)); }
16 
17 constexpr auto res = catty2(Foo<1>(Foo<0>()));
18