Fix PR30260 - optional<const T> not working.

This patch fixes PR30260 by using a (void*) cast on the placement argument to placement new to casts away the const. See also http://llvm.org/PR30260. As a drive by change this patch also changes the header guard for <experimental/optional> to _LIBCPP_EXPERIMENTAL_OPTIONAL from _LIBCPP_OPTIONAL. git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@280775 91177308-0d34-0410-b5e6-96231b3b80d8
2025-10-24 03:32:35 +08:00 · 2016-09-07 01:56:07 +00:00
parent 01609afe24
commit b9231a2326
9 changed files with 113 additions and 14 deletions
--- a/include/experimental/optional
+++ b/include/experimental/optional
@@ -8,8 +8,8 @@
 //
 //===----------------------------------------------------------------------===//

-#ifndef _LIBCPP_OPTIONAL
-#define _LIBCPP_OPTIONAL
+#ifndef _LIBCPP_EXPERIMENTAL_OPTIONAL
+#define _LIBCPP_EXPERIMENTAL_OPTIONAL

 /*
    optional synopsis
@@ -211,7 +211,7 @@ protected:
        :  __engaged_(__x.__engaged_)
        {
            if (__engaged_)
-                ::new(_VSTD::addressof(__val_)) value_type(__x.__val_);
+                ::new((void*)_VSTD::addressof(__val_)) value_type(__x.__val_);
        }

    _LIBCPP_INLINE_VISIBILITY
@@ -220,7 +220,7 @@ protected:
        :  __engaged_(__x.__engaged_)
        {
            if (__engaged_)
-                ::new(_VSTD::addressof(__val_)) value_type(_VSTD::move(__x.__val_));
+                ::new((void*)_VSTD::addressof(__val_)) value_type(_VSTD::move(__x.__val_));
        }

    _LIBCPP_INLINE_VISIBILITY
@@ -262,7 +262,7 @@ protected:
        :  __engaged_(__x.__engaged_)
        {
            if (__engaged_)
-                ::new(_VSTD::addressof(__val_)) value_type(__x.__val_);
+                ::new((void*)_VSTD::addressof(__val_)) value_type(__x.__val_);
        }

    _LIBCPP_INLINE_VISIBILITY
@@ -271,7 +271,7 @@ protected:
        :  __engaged_(__x.__engaged_)
        {
            if (__engaged_)
-                ::new(_VSTD::addressof(__val_)) value_type(_VSTD::move(__x.__val_));
+                ::new((void*)_VSTD::addressof(__val_)) value_type(_VSTD::move(__x.__val_));
        }

    _LIBCPP_INLINE_VISIBILITY
@@ -368,7 +368,7 @@ public:
            if (this->__engaged_)
                this->__val_.~value_type();
            else
-                ::new(_VSTD::addressof(this->__val_)) value_type(__opt.__val_);
+                ::new((void*)_VSTD::addressof(this->__val_)) value_type(__opt.__val_);
            this->__engaged_ = __opt.__engaged_;
        }
        return *this;
@@ -390,7 +390,8 @@ public:
            if (this->__engaged_)
                this->__val_.~value_type();
            else
-                ::new(_VSTD::addressof(this->__val_)) value_type(_VSTD::move(__opt.__val_));
+                ::new((void*)_VSTD::addressof(this->__val_))
+                    value_type(_VSTD::move(__opt.__val_));
            this->__engaged_ = __opt.__engaged_;
        }
        return *this;
@@ -412,7 +413,7 @@ public:
            this->__val_ = _VSTD::forward<_Up>(__v);
        else
        {
-            ::new(_VSTD::addressof(this->__val_)) value_type(_VSTD::forward<_Up>(__v));
+            ::new((void*)_VSTD::addressof(this->__val_)) value_type(_VSTD::forward<_Up>(__v));
            this->__engaged_ = true;
        }
        return *this;
@@ -429,7 +430,8 @@ public:
    emplace(_Args&&... __args)
    {
        *this = nullopt;
-        ::new(_VSTD::addressof(this->__val_)) value_type(_VSTD::forward<_Args>(__args)...);
+        ::new((void*)_VSTD::addressof(this->__val_))
+            value_type(_VSTD::forward<_Args>(__args)...);
        this->__engaged_ = true;
    }

@@ -444,7 +446,8 @@ public:
    emplace(initializer_list<_Up> __il, _Args&&... __args)
    {
        *this = nullopt;
-        ::new(_VSTD::addressof(this->__val_)) value_type(__il, _VSTD::forward<_Args>(__args)...);
+        ::new((void*)_VSTD::addressof(this->__val_))
+            value_type(__il, _VSTD::forward<_Args>(__args)...);
        this->__engaged_ = true;
    }

@@ -464,12 +467,14 @@ public:
        {
            if (this->__engaged_)
            {
-                ::new(_VSTD::addressof(__opt.__val_)) value_type(_VSTD::move(this->__val_));
+                ::new((void*)_VSTD::addressof(__opt.__val_))
+                    value_type(_VSTD::move(this->__val_));
                this->__val_.~value_type();
            }
            else
            {
-                ::new(_VSTD::addressof(this->__val_)) value_type(_VSTD::move(__opt.__val_));
+                ::new((void*)_VSTD::addressof(this->__val_))
+                    value_type(_VSTD::move(__opt.__val_));
                __opt.__val_.~value_type();
            }
            swap(this->__engaged_, __opt.__engaged_);
@@ -901,4 +906,4 @@ _LIBCPP_END_NAMESPACE_STD

 #endif  // _LIBCPP_STD_VER > 11

-#endif  // _LIBCPP_OPTIONAL
+#endif  // _LIBCPP_EXPERIMENTAL_OPTIONAL
--- a/test/std/experimental/optional/optional.object/optional.object.assign/assign_value.pass.cpp
+++ b/test/std/experimental/optional/optional.object/optional.object.assign/assign_value.pass.cpp
@@ -19,6 +19,14 @@

 using std::experimental::optional;

+struct AllowConstAssign {
+  AllowConstAssign() = default;
+  AllowConstAssign(AllowConstAssign const&) {}
+  AllowConstAssign const& operator=(AllowConstAssign const&) const {
+      return *this;
+  }
+};
+
 struct X
 {
 };
@@ -52,6 +60,11 @@ int main()
        assert(static_cast<bool>(opt) == true);
        assert(*opt == i);
    }
+    {
+        optional<const AllowConstAssign> opt;
+        const AllowConstAssign other;
+        opt = other;
+    }
    {
        optional<std::unique_ptr<int>> opt;
        opt = std::unique_ptr<int>(new int(3));
--- a/test/std/experimental/optional/optional.object/optional.object.assign/copy.pass.cpp
+++ b/test/std/experimental/optional/optional.object/optional.object.assign/copy.pass.cpp
@@ -19,6 +19,13 @@

 using std::experimental::optional;

+struct AllowConstAssign {
+  AllowConstAssign(AllowConstAssign const&) {}
+  AllowConstAssign const& operator=(AllowConstAssign const&) const {
+      return *this;
+  }
+};
+
 struct X
 {
    static bool throw_now;
@@ -42,6 +49,11 @@ int main()
        static_assert(static_cast<bool>(opt2) == false, "");
        assert(static_cast<bool>(opt) == static_cast<bool>(opt2));
    }
+    {
+        optional<const AllowConstAssign> opt;
+        optional<const AllowConstAssign> opt2;
+        opt = opt2;
+    }
    {
        optional<int> opt;
        constexpr optional<int> opt2(2);
--- a/test/std/experimental/optional/optional.object/optional.object.assign/emplace.pass.cpp
+++ b/test/std/experimental/optional/optional.object/optional.object.assign/emplace.pass.cpp
@@ -80,6 +80,12 @@ int main()
        assert(static_cast<bool>(opt) == true);
        assert(*opt == 1);
    }
+    {
+        optional<const int> opt(2);
+        opt.emplace(1);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == 1);
+    }
    {
        optional<X> opt;
        opt.emplace();
--- a/test/std/experimental/optional/optional.object/optional.object.assign/emplace_initializer_list.pass.cpp
+++ b/test/std/experimental/optional/optional.object/optional.object.assign/emplace_initializer_list.pass.cpp
@@ -81,6 +81,17 @@ int main()
            assert(*opt == X({1, 2}));
        }
    }
+    X::dtor_called = false;
+    {
+        X x;
+        {
+            optional<const X> opt(x);
+            assert(X::dtor_called == false);
+            opt.emplace({1, 2});
+            assert(X::dtor_called == true);
+            assert(*opt == X({1, 2}));
+        }
+    }
    {
        optional<std::vector<int>> opt;
        opt.emplace({1, 2, 3}, std::allocator<int>());
--- a/test/std/experimental/optional/optional.object/optional.object.assign/move.pass.cpp
+++ b/test/std/experimental/optional/optional.object/optional.object.assign/move.pass.cpp
@@ -21,6 +21,13 @@

 using std::experimental::optional;

+struct AllowConstAssign {
+  AllowConstAssign(AllowConstAssign const&) {}
+  AllowConstAssign const& operator=(AllowConstAssign const&) const {
+      return *this;
+  }
+};
+
 struct X
 {
    static bool throw_now;
@@ -76,6 +83,11 @@ int main()
        assert(static_cast<bool>(opt) == static_cast<bool>(opt2));
        assert(*opt == *opt2);
    }
+    {
+        optional<const AllowConstAssign> opt;
+        optional<const AllowConstAssign> opt2;
+        opt = std::move(opt2);
+    }
    {
        static_assert(!std::is_nothrow_move_assignable<optional<X>>::value, "");
        optional<X> opt;
--- a/test/std/experimental/optional/optional.object/optional.object.ctor/copy.pass.cpp
+++ b/test/std/experimental/optional/optional.object/optional.object.ctor/copy.pass.cpp
@@ -87,6 +87,11 @@ int main()
        optional<T> rhs(3);
        test(rhs);
    }
+    {
+        typedef const int T;
+        optional<T> rhs(3);
+        test(rhs);
+    }
    {
        typedef X T;
        optional<T> rhs;
@@ -97,6 +102,11 @@ int main()
        optional<T> rhs(X(3));
        test(rhs);
    }
+    {
+        typedef const X T;
+        optional<T> rhs(X(3));
+        test(rhs);
+    }
    {
        typedef Y T;
        optional<T> rhs;
--- a/test/std/experimental/optional/optional.object/optional.object.ctor/move.pass.cpp
+++ b/test/std/experimental/optional/optional.object/optional.object.ctor/move.pass.cpp
@@ -74,6 +74,17 @@ public:
    friend constexpr bool operator==(const Z& x, const Z& y) {return x.i_ == y.i_;}
 };

+
+class ConstMovable
+{
+    int i_;
+public:
+    ConstMovable(int i) : i_(i) {}
+    ConstMovable(const ConstMovable&& x) : i_(x.i_) {}
+    ~ConstMovable() {i_ = 0;}
+    friend bool operator==(const ConstMovable& x, const ConstMovable& y) {return x.i_ == y.i_;}
+};
+
 int main()
 {
    {
@@ -86,6 +97,11 @@ int main()
        optional<T> rhs(3);
        test(rhs);
    }
+    {
+        typedef const int T;
+        optional<T> rhs(3);
+        test(rhs);
+    }
    {
        typedef X T;
        optional<T> rhs;
@@ -96,6 +112,11 @@ int main()
        optional<T> rhs(X(3));
        test(rhs);
    }
+    {
+        typedef const ConstMovable T;
+        optional<T> rhs(ConstMovable(3));
+        test(rhs);
+    }
    {
        typedef Y T;
        optional<T> rhs;
--- a/test/std/experimental/optional/optional.object/optional.object.swap/swap.pass.cpp
+++ b/test/std/experimental/optional/optional.object/optional.object.swap/swap.pass.cpp
@@ -62,6 +62,10 @@ public:
    friend void swap(Z& x, Z& y) {throw 6;}
 };

+struct ConstSwappable {
+};
+void swap(ConstSwappable const&, ConstSwappable const&) {}
+
 int main()
 {
    {
@@ -112,6 +116,11 @@ int main()
        assert(static_cast<bool>(opt2) == true);
        assert(*opt2 == 1);
    }
+    {
+        optional<const ConstSwappable> opt;
+        optional<const ConstSwappable> opt2;
+        opt.swap(opt2);
+    }
    {
        optional<X> opt1;
        optional<X> opt2;