On 26 February 2018 at 22:52, Jonathan Wakely <jwak...@redhat.com> wrote:
> On 25/02/18 23:22 +0200, Ville Voutilainen wrote:
>>
>> Tested partially on Linux-x64, will test with the full suite on
>> Linux-PPC64.
>> Ok for trunk and the gcc-7 branch? This is theoretically a breaking change
> This template argument should be aligned with "_ValueType" on the
> previous line, not with "is_constructible".
>
> Looking at that file, I'm also wondering if we want the alias _AnyCast
> to be defined at namespace scope. It's only used in a few function
> bodies, and its name is a bit misleading.
>
> Could you just do:
>
> using _Up = remove_cv_t<remove_reference_t<_ValueType>>;
>
> in the four functions that use it?
>
> Then I think the is_constructible specializations would fit on one line
> anyway.
Done, new patch attached.
diff --git a/libstdc++-v3/include/std/any b/libstdc++-v3/include/std/any
index 466b7ca..a37eb38 100644
--- a/libstdc++-v3/include/std/any
+++ b/libstdc++-v3/include/std/any
@@ -438,8 +438,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
return any(in_place_type<_Tp>, __il, std::forward<_Args>(__args)...);
}
- template <typename _Tp>
- using _AnyCast = remove_cv_t<remove_reference_t<_Tp>>;
/**
* @brief Access the contained object.
*
@@ -453,9 +451,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _ValueType>
inline _ValueType any_cast(const any& __any)
{
+ using _Up = remove_cv_t<remove_reference_t<_ValueType>>;
static_assert(any::__is_valid_cast<_ValueType>(),
"Template argument must be a reference or CopyConstructible type");
- auto __p = any_cast<_AnyCast<_ValueType>>(&__any);
+ static_assert(is_constructible_v<_ValueType, const _Up&>,
+ "Template argument must be constructible from a const value.");
+ auto __p = any_cast<_Up>(&__any);
if (__p)
return static_cast<_ValueType>(*__p);
__throw_bad_any_cast();
@@ -476,37 +477,26 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _ValueType>
inline _ValueType any_cast(any& __any)
{
+ using _Up = remove_cv_t<remove_reference_t<_ValueType>>;
static_assert(any::__is_valid_cast<_ValueType>(),
"Template argument must be a reference or CopyConstructible type");
- auto __p = any_cast<_AnyCast<_ValueType>>(&__any);
+ static_assert(is_constructible_v<_ValueType, _Up&>,
+ "Template argument must be constructible from an lvalue.");
+ auto __p = any_cast<_Up>(&__any);
if (__p)
return static_cast<_ValueType>(*__p);
__throw_bad_any_cast();
}
- template<typename _ValueType,
- typename enable_if<!is_move_constructible<_ValueType>::value
- || is_lvalue_reference<_ValueType>::value,
- bool>::type = true>
- inline _ValueType any_cast(any&& __any)
- {
- static_assert(any::__is_valid_cast<_ValueType>(),
- "Template argument must be a reference or CopyConstructible type");
- auto __p = any_cast<_AnyCast<_ValueType>>(&__any);
- if (__p)
- return static_cast<_ValueType>(*__p);
- __throw_bad_any_cast();
- }
-
- template<typename _ValueType,
- typename enable_if<is_move_constructible<_ValueType>::value
- && !is_lvalue_reference<_ValueType>::value,
- bool>::type = false>
+ template<typename _ValueType>
inline _ValueType any_cast(any&& __any)
{
+ using _Up = remove_cv_t<remove_reference_t<_ValueType>>;
static_assert(any::__is_valid_cast<_ValueType>(),
"Template argument must be a reference or CopyConstructible type");
- auto __p = any_cast<_AnyCast<_ValueType>>(&__any);
+ static_assert(is_constructible_v<_ValueType, _Up>,
+ "Template argument must be constructible from an rvalue.");
+ auto __p = any_cast<_Up>(&__any);
if (__p)
return static_cast<_ValueType>(std::move(*__p));
__throw_bad_any_cast();
diff --git a/libstdc++-v3/testsuite/20_util/any/misc/any_cast.cc
b/libstdc++-v3/testsuite/20_util/any/misc/any_cast.cc
index 45d8b63..37a24d7 100644
--- a/libstdc++-v3/testsuite/20_util/any/misc/any_cast.cc
+++ b/libstdc++-v3/testsuite/20_util/any/misc/any_cast.cc
@@ -95,15 +95,6 @@ void test03()
VERIFY(move_count == 1);
MoveEnabled&& m3 = any_cast<MoveEnabled&&>(any(m));
VERIFY(move_count == 1);
- struct MoveDeleted
- {
- MoveDeleted(MoveDeleted&&) = delete;
- MoveDeleted() = default;
- MoveDeleted(const MoveDeleted&) = default;
- };
- MoveDeleted md;
- MoveDeleted&& md2 = any_cast<MoveDeleted>(any(std::move(md)));
- MoveDeleted&& md3 = any_cast<MoveDeleted&&>(any(std::move(md)));
}
void test04()
diff --git a/libstdc++-v3/testsuite/20_util/any/misc/any_cast_neg.cc
b/libstdc++-v3/testsuite/20_util/any/misc/any_cast_neg.cc
index 50a9a67..62d7aaa 100644
--- a/libstdc++-v3/testsuite/20_util/any/misc/any_cast_neg.cc
+++ b/libstdc++-v3/testsuite/20_util/any/misc/any_cast_neg.cc
@@ -20,11 +20,26 @@
#include <any>
+using std::any;
+using std::any_cast;
+
void test01()
{
- using std::any;
- using std::any_cast;
-
const any y(1);
- any_cast<int&>(y); // { dg-error "invalid static_cast" "" { target { *-*-* }
} 460 }
+ any_cast<int&>(y); // { dg-error "invalid static_cast" "" { target { *-*-* }
} 461 }
+ // { dg-error "Template argument must be constructible from a const value"
"" { target { *-*-* } } 457 }
+}
+
+void test02()
+{
+ any y(1);
+ any_cast<int&&>(y);
+ // { dg-error "Template argument must be constructible from an lvalue" "" {
target { *-*-* } } 483 }
+}
+
+void test03()
+{
+ any y(1);
+ any_cast<int&>(std::move(y)); // { dg-error "invalid static_cast" "" {
target { *-*-* } } 501 }
+ // { dg-error "Template argument must be constructible from an rvalue" "" {
target { *-*-* } } 497 }
}
