diff options
Diffstat (limited to 'gcc')
-rw-r--r-- | gcc/testsuite/g++.dg/cpp0x/variadic-alias8.C | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/gcc/testsuite/g++.dg/cpp0x/variadic-alias8.C b/gcc/testsuite/g++.dg/cpp0x/variadic-alias8.C new file mode 100644 index 0000000..1d317ef --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/variadic-alias8.C @@ -0,0 +1,95 @@ +// PR c++/101071 +// { dg-do compile { target c++11 } } +// { dg-additional-options "-fno-elide-constructors -O2" } + +// Like variadic-alias2.C, just different options. + +template<class...> +struct list {}; + +struct nil; + +//////////////////////////////////////////////////////////////////////////////// + +template<int n> +struct number { + constexpr /*implicit*/ operator int() const { return n; } + using type = number<n>; +}; + +using false_ = number<0>; +using true_ = number<1>; + +static_assert(!false_{}, ""); +static_assert(true_{}, ""); + +template<int... ns> using numbers = list<number<ns>...>; + +//////////////////////////////////////////////////////////////////////////////// + +template<class lhs, class rhs> +struct less_impl; + +template<int lhs, int rhs> +struct less_impl<number<lhs>, number<rhs>> + : number<(lhs < rhs)> {}; + +template<class lhs, class rhs> using less = typename less_impl<lhs, rhs>::type; + +//////////////////////////////////////////////////////////////////////////////// + +template<class v0, class... vs> +struct sum_impl { + static_assert(sizeof...(vs) == 0, "see specialization"); + using type = v0; +}; + +template<int v0, int v1, class... vs> +struct sum_impl<number<v0>, number<v1>, vs...> + : sum_impl<number<v0 + v1>, vs...> {}; + +template<class... nums> using sum = typename sum_impl<nums...>::type; + +//////////////////////////////////////////////////////////////////////////////// + +template<class num> +struct conditional_impl { + static_assert(num{}, "see specialization"); + + template<class T, class F> + using type = T; +}; + +template<> +struct conditional_impl<false_> { + template<class T, class F> + using type = F; +}; + +template<class num, class T, class F> +using conditional = typename conditional_impl<num>::template type<T, F>; + +//////////////////////////////////////////////////////////////////////////////// + +template<class seq> +struct min_filter_impl; + +template<class... nums> +struct min_filter_impl<list<nums...>> { + template<class num> + using count_better_mins = sum<less<nums, num>...>; + + using type = list<conditional<count_better_mins<nums>, nil, nums>...>; +}; + +template<class seq> using min_filter = typename min_filter_impl<seq>::type; + +//////////////////////////////////////////////////////////////////////////////// + +void test_min_filter() { + using computed = min_filter<numbers<2, 7, 2>>; + using expected = list<number<2>, nil, number<2>>; + (void)(computed{} = expected{});// compiles for identical types +} + +int main() {} |