[libcxx] Add std::any

Summary:
This patch adds std::any by moving/adapting <experimental/any>.

This patch also implements the std::any parts of p0032r3 (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0032r3.pdf)
and LWG 2509 (http://cplusplus.github.io/LWG/lwg-defects.html#2509).

I plan to push it in a day or two if there are no comments.


Reviewers: mclow.lists, EricWF

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D22733

llvm-svn: 278310

1 files changed, 205 insertions, 0 deletions

diff --git a/libcxx/test/std/utilities/any/any.class/any.assign/value.pass.cpp b/libcxx/test/std/utilities/any/any.class/any.assign/value.pass.cpp
new file mode 100644
index 00000000000..d844fcfaa7c
--- /dev/null
+++ b/libcxx/test/std/utilities/any/any.class/any.assign/value.pass.cpp
@@ -0,0 +1,205 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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
+
+// <any>
+
+// any& operator=(any const &);
+
+// Test value copy and move assignment.
+
+#include <any>
+#include <cassert>
+
+#include "any_helpers.h"
+#include "count_new.hpp"
+#include "test_macros.h"
+
+using std::any;
+using std::any_cast;
+
+template <class LHS, class RHS>
+void test_assign_value() {
+    assert(LHS::count == 0);
+    assert(RHS::count == 0);
+    LHS::reset();
+    RHS::reset();
+    {
+        any lhs(LHS(1));
+        any const rhs(RHS(2));
+
+        assert(LHS::count == 1);
+        assert(RHS::count == 1);
+        assert(RHS::copied == 0);
+
+        lhs = rhs;
+
+        assert(RHS::copied == 1);
+        assert(LHS::count == 0);
+        assert(RHS::count == 2);
+
+        assertContains<RHS>(lhs, 2);
+        assertContains<RHS>(rhs, 2);
+    }
+    assert(LHS::count == 0);
+    assert(RHS::count == 0);
+    LHS::reset();
+    RHS::reset();
+    {
+        any lhs(LHS(1));
+        any rhs(RHS(2));
+
+        assert(LHS::count == 1);
+        assert(RHS::count == 1);
+        assert(RHS::moved == 1);
+
+        lhs = std::move(rhs);
+
+        assert(RHS::moved >= 1);
+        assert(RHS::copied == 0);
+        assert(LHS::count == 0);
+        assert(RHS::count == 1);
+
+        assertContains<RHS>(lhs, 2);
+        assertEmpty<RHS>(rhs);
+    }
+    assert(LHS::count == 0);
+    assert(RHS::count == 0);
+}
+
+template <class RHS>
+void test_assign_value_empty() {
+    assert(RHS::count == 0);
+    RHS::reset();
+    {
+        any lhs;
+        RHS rhs(42);
+        assert(RHS::count == 1);
+        assert(RHS::copied == 0);
+
+        lhs = rhs;
+
+        assert(RHS::count == 2);
+        assert(RHS::copied == 1);
+        assert(RHS::moved >= 0);
+        assertContains<RHS>(lhs, 42);
+    }
+    assert(RHS::count == 0);
+    RHS::reset();
+    {
+        any lhs;
+        RHS rhs(42);
+        assert(RHS::count == 1);
+        assert(RHS::moved == 0);
+
+        lhs = std::move(rhs);
+
+        assert(RHS::count == 2);
+        assert(RHS::copied == 0);
+        assert(RHS::moved >= 1);
+        assertContains<RHS>(lhs, 42);
+    }
+    assert(RHS::count == 0);
+    RHS::reset();
+}
+
+
+template <class Tp, bool Move = false>
+void test_assign_throws() {
+#if !defined(TEST_HAS_NO_EXCEPTIONS)
+    auto try_throw=
+    [](any& lhs, auto&& rhs) {
+        try {
+            Move ? lhs = std::move(rhs)
+                 : lhs = rhs;
+            assert(false);
+        } catch (my_any_exception const &) {
+            // do nothing
+        } catch (...) {
+            assert(false);
+        }
+    };
+    // const lvalue to empty
+    {
+        any lhs;
+        Tp rhs(1);
+        assert(Tp::count == 1);
+
+        try_throw(lhs, rhs);
+
+        assert(Tp::count == 1);
+        assertEmpty<Tp>(lhs);
+    }
+    {
+        any lhs((small(2)));
+        Tp  rhs(1);
+        assert(small::count == 1);
+        assert(Tp::count == 1);
+
+        try_throw(lhs, rhs);
+
+        assert(small::count == 1);
+        assert(Tp::count == 1);
+        assertContains<small>(lhs, 2);
+    }
+    {
+        any lhs((large(2)));
+        Tp rhs(1);
+        assert(large::count == 1);
+        assert(Tp::count == 1);
+
+        try_throw(lhs, rhs);
+
+        assert(large::count == 1);
+        assert(Tp::count == 1);
+        assertContains<large>(lhs, 2);
+    }
+#endif
+}
+
+
+// Test that any& operator=(ValueType&&) is *never* selected for:
+// * std::in_place type.
+// * Non-copyable types
+void test_sfinae_constraints() {
+    {
+        using Tag = std::in_place_type_t<int>;
+        using RawTag = std::remove_reference_t<Tag>;
+        static_assert(!std::is_assignable<std::any, RawTag&&>::value, "");
+    }
+    {
+        struct Dummy { Dummy() = delete; };
+        using T = std::in_place_type_t<Dummy>;
+        static_assert(!std::is_assignable<std::any, T>::value, "");
+    }
+    {
+        // Test that the ValueType&& constructor SFINAE's away when the
+        // argument is non-copyable
+        struct NoCopy {
+          NoCopy() = default;
+          NoCopy(NoCopy const&) = delete;
+          NoCopy(NoCopy&&) = default;
+        };
+        static_assert(!std::is_assignable<std::any, NoCopy>::value, "");
+    }
+}
+
+int main() {
+    test_assign_value<small1, small2>();
+    test_assign_value<large1, large2>();
+    test_assign_value<small, large>();
+    test_assign_value<large, small>();
+    test_assign_value_empty<small>();
+    test_assign_value_empty<large>();
+    test_assign_throws<small_throws_on_copy>();
+    test_assign_throws<large_throws_on_copy>();
+    test_assign_throws<throws_on_move, /* Move = */ true>();
+    test_sfinae_constraints();
+}
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