init

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

@@ -0,0 +1,129 @@
+/// \file
+// Range v3 library
+//
+//  Copyright Andrey Diduh 2019
+//
+//  Use, modification and distribution is subject to the
+//  Boost Software License, Version 1.0. (See accompanying
+//  file LICENSE_1_0.txt or copy at
+//  http://www.boost.org/LICENSE_1_0.txt)
+//
+// Project home: https://github.com/ericniebler/range-v3
+//
+
+#include <sstream>
+#include <vector>
+
+#include <range/v3/core.hpp>
+#include <range/v3/view/addressof.hpp>
+#include <range/v3/view/facade.hpp>
+#include <range/v3/view/iota.hpp>
+#include <range/v3/view/take.hpp>
+
+#include "../simple_test.hpp"
+#include "../test_utils.hpp"
+
+using namespace ranges;
+
+void simple_test()
+{
+    std::vector<int> list = {1,2,3};
+
+    auto out = list | views::addressof;
+
+    check_equal(out, {&list[0], &list[1], &list[2]});
+}
+
+struct test_istream_range
+  : view_facade<test_istream_range, unknown>
+{
+private:
+    friend range_access;
+
+    std::vector<int> *list;
+
+    struct cursor
+    {
+    private:
+        std::size_t i = 0;
+        std::vector<int> *list = nullptr;
+    public:
+        cursor() = default;
+        explicit cursor(std::vector<int> &list_)
+          : list(&list_)
+        {}
+        void next()
+        {
+            ++i;
+        }
+        int &read() const noexcept
+        {
+            return (*list)[i];
+        }
+        bool equal(default_sentinel_t) const
+        {
+            return i == list->size();
+        }
+    };
+
+    cursor begin_cursor()
+    {
+        return cursor{*list};
+    }
+public:
+    test_istream_range() = default;
+    explicit test_istream_range(std::vector<int> &list_)
+      : list(&list_)
+    {}
+};
+
+void test_input_range()
+{
+    // It is implementation dependent,
+    // for how long returned reference remains valid.
+    // It should be valid at least until next read.
+    // For test purposes we use custom input range.
+
+    std::vector<int> list{1, 2, 3};
+    auto rng = test_istream_range(list);
+    CPP_assert(input_range<decltype(rng)>);
+
+    auto out = rng | views::addressof;
+    check_equal(out, {&list[0], &list[1], &list[2]});
+}
+
+struct test_xvalue_range
+  : view_facade<test_xvalue_range, unknown>
+{
+private:
+    friend range_access;
+
+    struct cursor
+    {
+        cursor() = default;
+        void next();
+        int &&read() const noexcept;
+        bool equal(default_sentinel_t) const;
+    };
+
+    cursor begin_cursor();
+};
+
+template<typename, typename = void>
+constexpr bool can_view = false;
+template<typename R>
+constexpr bool can_view<R,
+    meta::void_<decltype(views::addressof(std::declval<R>()))>> = true;
+
+// prvalue ranges cannot be passed to views::addressof
+CPP_assert(!can_view<decltype(views::iota(0, 3))>);
+// xvalue ranges cannot be passed to views::addressof
+CPP_assert(!can_view<test_xvalue_range>);
+
+int main()
+{
+    simple_test();
+    test_input_range();
+
+    return test_result();
+}