1 files changed, 232 insertions, 0 deletions
diff --git a/test/std/utilities/variant/variant.variant/variant.assign/T.pass.cpp b/test/std/utilities/variant/variant.variant/variant.assign/T.pass.cpp
new file mode 100644
index 000000000000..10022b14aa06
--- /dev/null
+++ b/test/std/utilities/variant/variant.variant/variant.assign/T.pass.cpp
@@ -0,0 +1,232 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+
+// <variant>
+
+// template <class ...Types> class variant;
+
+// template <class T>
+// variant& operator=(T&&) noexcept(see below);
+
+#include <cassert>
+#include <string>
+#include <type_traits>
+#include <variant>
+
+#include "test_macros.h"
+#include "variant_test_helpers.hpp"
+
+namespace MetaHelpers {
+
+struct Dummy {
+  Dummy() = default;
+};
+
+struct ThrowsCtorT {
+  ThrowsCtorT(int) noexcept(false) {}
+  ThrowsCtorT &operator=(int) noexcept { return *this; }
+};
+
+struct ThrowsAssignT {
+  ThrowsAssignT(int) noexcept {}
+  ThrowsAssignT &operator=(int) noexcept(false) { return *this; }
+};
+
+struct NoThrowT {
+  NoThrowT(int) noexcept {}
+  NoThrowT &operator=(int) noexcept { return *this; }
+};
+
+} // namespace MetaHelpers
+
+namespace RuntimeHelpers {
+#ifndef TEST_HAS_NO_EXCEPTIONS
+
+struct ThrowsCtorT {
+  int value;
+  ThrowsCtorT() : value(0) {}
+  ThrowsCtorT(int) noexcept(false) { throw 42; }
+  ThrowsCtorT &operator=(int v) noexcept {
+    value = v;
+    return *this;
+  }
+};
+
+struct ThrowsAssignT {
+  int value;
+  ThrowsAssignT() : value(0) {}
+  ThrowsAssignT(int v) noexcept : value(v) {}
+  ThrowsAssignT &operator=(int) noexcept(false) { throw 42; }
+};
+
+struct NoThrowT {
+  int value;
+  NoThrowT() : value(0) {}
+  NoThrowT(int v) noexcept : value(v) {}
+  NoThrowT &operator=(int v) noexcept {
+    value = v;
+    return *this;
+  }
+};
+
+#endif // !defined(TEST_HAS_NO_EXCEPTIONS)
+} // namespace RuntimeHelpers
+
+void test_T_assignment_noexcept() {
+  using namespace MetaHelpers;
+  {
+    using V = std::variant<Dummy, NoThrowT>;
+    static_assert(std::is_nothrow_assignable<V, int>::value, "");
+  }
+  {
+    using V = std::variant<Dummy, ThrowsCtorT>;
+    static_assert(!std::is_nothrow_assignable<V, int>::value, "");
+  }
+  {
+    using V = std::variant<Dummy, ThrowsAssignT>;
+    static_assert(!std::is_nothrow_assignable<V, int>::value, "");
+  }
+}
+
+void test_T_assignment_sfinae() {
+  {
+    using V = std::variant<long, unsigned>;
+    static_assert(!std::is_assignable<V, int>::value, "ambiguous");
+  }
+  {
+    using V = std::variant<std::string, std::string>;
+    static_assert(!std::is_assignable<V, const char *>::value, "ambiguous");
+  }
+  {
+    using V = std::variant<std::string, void *>;
+    static_assert(!std::is_assignable<V, int>::value, "no matching operator=");
+  }
+#if !defined(TEST_VARIANT_HAS_NO_REFERENCES)
+  {
+    using V = std::variant<int, int &&>;
+    static_assert(!std::is_assignable<V, int>::value, "ambiguous");
+  }
+  {
+    using V = std::variant<int, const int &>;
+    static_assert(!std::is_assignable<V, int>::value, "ambiguous");
+  }
+#endif
+}
+
+void test_T_assignment_basic() {
+  {
+    std::variant<int> v(43);
+    v = 42;
+    assert(v.index() == 0);
+    assert(std::get<0>(v) == 42);
+  }
+  {
+    std::variant<int, long> v(43l);
+    v = 42;
+    assert(v.index() == 0);
+    assert(std::get<0>(v) == 42);
+    v = 43l;
+    assert(v.index() == 1);
+    assert(std::get<1>(v) == 43);
+  }
+#if !defined(TEST_VARIANT_HAS_NO_REFERENCES)
+  {
+    using V = std::variant<int &, int &&, long>;
+    int x = 42;
+    V v(43l);
+    v = x;
+    assert(v.index() == 0);
+    assert(&std::get<0>(v) == &x);
+    v = std::move(x);
+    assert(v.index() == 1);
+    assert(&std::get<1>(v) == &x);
+    // 'long' is selected by FUN(const int &) since 'const int &' cannot bind
+    // to 'int&'.
+    const int &cx = x;
+    v = cx;
+    assert(v.index() == 2);
+    assert(std::get<2>(v) == 42);
+  }
+#endif
+}
+
+void test_T_assignment_performs_construction() {
+  using namespace RuntimeHelpers;
+#ifndef TEST_HAS_NO_EXCEPTIONS
+  {
+    using V = std::variant<std::string, ThrowsCtorT>;
+    V v(std::in_place_type<std::string>, "hello");
+    try {
+      v = 42;
+    } catch (...) { /* ... */
+    }
+    assert(v.valueless_by_exception());
+  }
+  {
+    using V = std::variant<ThrowsAssignT, std::string>;
+    V v(std::in_place_type<std::string>, "hello");
+    v = 42;
+    assert(v.index() == 0);
+    assert(std::get<0>(v).value == 42);
+  }
+#endif
+}
+
+void test_T_assignment_performs_assignment() {
+  using namespace RuntimeHelpers;
+#ifndef TEST_HAS_NO_EXCEPTIONS
+  {
+    using V = std::variant<ThrowsCtorT>;
+    V v;
+    v = 42;
+    assert(v.index() == 0);
+    assert(std::get<0>(v).value == 42);
+  }
+  {
+    using V = std::variant<ThrowsCtorT, std::string>;
+    V v;
+    v = 42;
+    assert(v.index() == 0);
+    assert(std::get<0>(v).value == 42);
+  }
+  {
+    using V = std::variant<ThrowsAssignT>;
+    V v(100);
+    try {
+      v = 42;
+      assert(false);
+    } catch (...) { /* ... */
+    }
+    assert(v.index() == 0);
+    assert(std::get<0>(v).value == 100);
+  }
+  {
+    using V = std::variant<std::string, ThrowsAssignT>;
+    V v(100);
+    try {
+      v = 42;
+      assert(false);
+    } catch (...) { /* ... */
+    }
+    assert(v.index() == 1);
+    assert(std::get<1>(v).value == 100);
+  }
+#endif
+}
+
+int main() {
+  test_T_assignment_basic();
+  test_T_assignment_performs_construction();
+  test_T_assignment_performs_assignment();
+  test_T_assignment_noexcept();
+  test_T_assignment_sfinae();
+}