init

Telegram/ThirdParty/range-v3/test/view/view.cpp

@@ -0,0 +1,49 @@
+#include <vector>
+
+#include <range/v3/view/drop.hpp>
+#include <range/v3/view/view.hpp>
+
+#include "../simple_test.hpp"
+#include "../test_utils.hpp"
+
+using namespace ranges;
+
+struct my_drop_base_fn
+{
+    template<typename Rng>
+    auto operator()(Rng && rng, range_difference_t<Rng> n) const
+    {
+        return drop_view<views::all_t<Rng>>(views::all(static_cast<Rng &&>(rng)), n);
+    }
+};
+struct my_drop_fn : my_drop_base_fn
+{
+    using my_drop_base_fn::operator();
+
+    template<typename Int>
+    constexpr auto operator()(Int n) const
+    {
+        return make_view_closure([=](auto && rng) {
+            return my_drop_base_fn{}(std::forward<decltype(rng)>(rng), n); });
+    }
+};
+RANGES_INLINE_VARIABLE(my_drop_fn, my_drop)
+
+/// #https://github.com/ericniebler/range-v3/issues/1169
+void constexpr_test_1169()
+{
+#if RANGES_CXX_CONSTEXPR >= RANGES_CXX_CONSTEXPR_LAMBDAS
+    constexpr auto const drop1 = my_drop(1);
+    constexpr auto const drop3 = drop1 | my_drop(2);
+
+    std::vector<int> vec = {1, 2, 3, 4};
+    check_equal(vec | drop3, {4});
+#endif
+    (void)my_drop;
+}
+
+int main()
+{
+    constexpr_test_1169();
+    return test_result();
+}