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// PR c++/59867
// { dg-do compile { target c++1y } }
#include <iostream>
using namespace std;
// constant
template<typename T, T x>
struct meta_value
{
typedef meta_value type;
typedef T value_type;
static const T value = x;
};
// array
template<typename T, T... data>
struct meta_array
{
typedef meta_array type;
typedef T item_type;
};
// static array -> runtime array conversion utility
template<typename T>
struct array_gen;
template<typename T, T... xs>
struct array_gen<meta_array<T, xs...>>
{
static const T value[sizeof...(xs)];
};
template<typename T, T... xs>
const T
array_gen<meta_array<T, xs...>>::value[sizeof...(xs)] = {xs...};
// static string
template<typename T, T... xs>
constexpr meta_array<T, xs...>
operator""_s()
{
static_assert(sizeof...(xs) == 3, "What's wrong with you?");
return meta_array<T, xs...>();
}
int
main()
{
auto a = "123"_s;
const char (& xs)[3] = array_gen<decltype("123"_s)>::value;
}
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