airthmetic test

Author: changkhothuychung

libcxx/test/std/ranges/range.adaptors/range.concat/iterator/arithmetic.pass.cpp

@@ -0,0 +1,109 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// REQUIRES: std-at-least-c++26
+
+#include <ranges>
+
+#include <array>
+#include <concepts>
+#include <functional>
+
+#include "../../range_adaptor_types.h"
+
+template <class T, class U>
+concept canPlusEqual = requires(T& t, U& u) { t += u; };
+
+template <class T, class U>
+concept canMinusEqual = requires(T& t, U& u) { t -= u; };
+
+constexpr bool test() {
+  int buffer1[5] = {1, 2, 3, 4, 5};
+  int buffer2[9] = {1, 2, 3, 4, 5, 6, 7, 8, 9};
+
+  SimpleCommonRandomAccessSized a{buffer1};
+  SimpleCommonRandomAccessSized b{buffer2};
+
+  {
+    // operator+(x, n) and operator+=
+    std::ranges::concat_view v(a, b);
+    auto it1 = v.begin();
+
+    auto it2 = it1 + 3;
+    auto x2  = *it2;
+    assert(x2 == buffer1[3]);
+
+    auto it3 = 3 + it1;
+    auto x3  = *it3;
+    assert(x3 == buffer1[3]);
+
+    it1 += 3;
+    assert(it1 == it2);
+    auto x1 = *it2;
+    assert(x1 == buffer1[3]);
+
+    using Iter = decltype(it1);
+    static_assert(canPlusEqual<Iter, std::intptr_t>);
+  }
+
+  {
+    // operator-(x, n) and operator-=
+    std::ranges::concat_view v(a, b);
+    auto it1 = v.end();
+
+    auto it2 = it1 - 3;
+    auto x2  = *it2;
+    assert(x2 == buffer2[6]);
+
+    it1 -= 3;
+    assert(it1 == it2);
+    auto x1 = *it2;
+    assert(x1 == buffer2[6]);
+
+    using Iter = decltype(it1);
+    static_assert(canMinusEqual<Iter, std::intptr_t>);
+  }
+
+  {
+    // operator-(x, y)
+    std::ranges::concat_view v(a, b);
+    assert((v.end() - v.begin()) == 14);
+
+    auto it1 = v.begin() + 2;
+    auto it2 = v.end() - 1;
+    assert((it1 - it2) == -11);
+  }
+
+  {
+    // One of the ranges is not random access
+    std::ranges::concat_view v(a, b, ForwardSizedView{buffer1});
+    using Iter = decltype(v.begin());
+    static_assert(!std::invocable<std::plus<>, Iter, std::intptr_t>);
+    static_assert(!std::invocable<std::plus<>, std::intptr_t, Iter>);
+    static_assert(!canPlusEqual<Iter, std::intptr_t>);
+    static_assert(!std::invocable<std::minus<>, Iter, std::intptr_t>);
+    static_assert(!std::invocable<std::minus<>, Iter, Iter>);
+    static_assert(!canMinusEqual<Iter, std::intptr_t>);
+  }
+
+  {
+    // One of the ranges does not have sized sentinel
+    std::ranges::concat_view v(a, b, InputCommonView{buffer1});
+    using Iter = decltype(v.begin());
+    static_assert(!std::invocable<std::minus<>, Iter, Iter>);
+  }
+
+  return true;
+}
+
+int main(int, char**) {
+  test();
+  static_assert(test());
+
+  return 0;
+}