1 // { dg-do compile { target c++11 } }
2
3 template<class T>
do_last(T * x,int n)4 constexpr T do_last(T* x, int n) {
5 return x[n - 1]; //
6 }
7
8 template<class T, int N>
last(T (& x)[N])9 constexpr T last(T (&x)[N]) {
10 return do_last(x, N);
11 }
12
is_negative(int x)13 constexpr bool is_negative(int x) { return x < 0; }
14
15 template<class T>
16 struct IsNegative {
operatorIsNegative17 constexpr bool operator()(const T& x) {
18 return x < T(0);
19 }
20 };
21
22 template<class T, int N, class Pred>
has_neg(T (& x)[N],Pred p)23 constexpr bool has_neg(T (&x)[N], Pred p) {
24 return p(last(x)); // Line 22
25 }
26
27 constexpr int a[] = {1, -2};
28
29 constexpr auto answer1 = has_neg(a, IsNegative<int>{}); // Line 27
30 constexpr auto answer2 = has_neg(a, is_negative);
31
32 static_assert(answer2 == answer1, "Error");
33