[cfe-commits] [libcxx] r153855 - in /libcxx/trunk: include/__tuple include/tuple test/utilities/tuple/tuple.tuple/tuple.cnstr/UTypes.fail.cpp test/utilities/tuple/tuple.tuple/tuple.cnstr/const_Types.fail.cpp
Howard Hinnant
hhinnant at apple.com
Sun Apr 1 16:10:42 PDT 2012
Author: hhinnant
Date: Sun Apr 1 18:10:42 2012
New Revision: 153855
URL: http://llvm.org/viewvc/llvm-project?rev=153855&view=rev
Log:
I believe tuple is still under development in the standard. Daniel Krugler is/will be making convincing arguments that a modified form of LWG 2051 (currently NAD Future) is easily acheivable and desirable. He has demonstrated that a tuple<T...> where all of the T are implicitly convertible from U... should have a tuple constructor that is also implicit, instead of explicit. This would support the use cases in LWG 2051 while not undermining T... with explicit conversions from U.... This check-in is an experimental implementation of Daniel's work. I believe this work to be mature enough to warrant inclusion into libc++. If anyone sees real-world problems that this check in causes, please let me know and I will revert it, and provide the feedback to the LWG.
Modified:
libcxx/trunk/include/__tuple
libcxx/trunk/include/tuple
libcxx/trunk/test/utilities/tuple/tuple.tuple/tuple.cnstr/UTypes.fail.cpp
libcxx/trunk/test/utilities/tuple/tuple.tuple/tuple.cnstr/const_Types.fail.cpp
Modified: libcxx/trunk/include/__tuple
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/__tuple?rev=153855&r1=153854&r2=153855&view=diff
==============================================================================
--- libcxx/trunk/include/__tuple (original)
+++ libcxx/trunk/include/__tuple Sun Apr 1 18:10:42 2012
@@ -216,7 +216,7 @@
template <class _Tp0, class ..._Tp, class _Up0, class ..._Up>
struct __tuple_convertible_imp<true, __tuple_types<_Tp0, _Tp...>, __tuple_types<_Up0, _Up...> >
: public integral_constant<bool,
- is_constructible<_Up0, _Tp0>::value &&
+ is_convertible<_Tp0, _Up0>::value &&
__tuple_convertible_imp<true, __tuple_types<_Tp...>, __tuple_types<_Up...> >::value> {};
template <>
@@ -235,6 +235,33 @@
typename __make_tuple_types<_Tp>::type, typename __make_tuple_types<_Up>::type>
{};
+// __tuple_constructible
+
+template <bool, class _Tp, class _Up>
+struct __tuple_constructible_imp : public false_type {};
+
+template <class _Tp0, class ..._Tp, class _Up0, class ..._Up>
+struct __tuple_constructible_imp<true, __tuple_types<_Tp0, _Tp...>, __tuple_types<_Up0, _Up...> >
+ : public integral_constant<bool,
+ is_constructible<_Up0, _Tp0>::value &&
+ __tuple_constructible_imp<true, __tuple_types<_Tp...>, __tuple_types<_Up...> >::value> {};
+
+template <>
+struct __tuple_constructible_imp<true, __tuple_types<>, __tuple_types<> >
+ : public true_type {};
+
+template <class _Tp, class _Up, bool = __tuple_like<typename remove_reference<_Tp>::type>::value,
+ bool = __tuple_like<_Up>::value>
+struct __tuple_constructible
+ : public false_type {};
+
+template <class _Tp, class _Up>
+struct __tuple_constructible<_Tp, _Up, true, true>
+ : public __tuple_constructible_imp<tuple_size<typename remove_reference<_Tp>::type>::value ==
+ tuple_size<_Up>::value,
+ typename __make_tuple_types<_Tp>::type, typename __make_tuple_types<_Up>::type>
+{};
+
// __tuple_assignable
template <bool, class _Tp, class _Up>
Modified: libcxx/trunk/include/tuple
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/tuple?rev=153855&r1=153854&r2=153855&view=diff
==============================================================================
--- libcxx/trunk/include/tuple (original)
+++ libcxx/trunk/include/tuple Sun Apr 1 18:10:42 2012
@@ -552,7 +552,7 @@
) {}
template <class ..._Up,
- class = typename enable_if
+ typename enable_if
<
sizeof...(_Up) <= sizeof...(_Tp) &&
__tuple_convertible
@@ -562,8 +562,40 @@
sizeof...(_Up) < sizeof...(_Tp) ?
sizeof...(_Up) :
sizeof...(_Tp)>::type
- >::value
- >::type
+ >::value,
+ bool
+ >::type = false
+ >
+ _LIBCPP_INLINE_VISIBILITY
+ tuple(_Up&&... __u)
+ : base_(typename __make_tuple_indices<sizeof...(_Up)>::type(),
+ typename __make_tuple_types<tuple, sizeof...(_Up)>::type(),
+ typename __make_tuple_indices<sizeof...(_Tp), sizeof...(_Up)>::type(),
+ typename __make_tuple_types<tuple, sizeof...(_Tp), sizeof...(_Up)>::type(),
+ _VSTD::forward<_Up>(__u)...) {}
+
+ template <class ..._Up,
+ typename enable_if
+ <
+ sizeof...(_Up) <= sizeof...(_Tp) &&
+ __tuple_constructible
+ <
+ tuple<_Up...>,
+ typename __make_tuple_types<tuple,
+ sizeof...(_Up) < sizeof...(_Tp) ?
+ sizeof...(_Up) :
+ sizeof...(_Tp)>::type
+ >::value &&
+ !__tuple_convertible
+ <
+ tuple<_Up...>,
+ typename __make_tuple_types<tuple,
+ sizeof...(_Up) < sizeof...(_Tp) ?
+ sizeof...(_Up) :
+ sizeof...(_Tp)>::type
+ >::value,
+ bool
+ >::type =false
>
_LIBCPP_INLINE_VISIBILITY
explicit
@@ -598,15 +630,29 @@
_VSTD::forward<_Up>(__u)...) {}
template <class _Tuple,
- class = typename enable_if
+ typename enable_if
<
- __tuple_convertible<_Tuple, tuple>::value
- >::type
+ __tuple_convertible<_Tuple, tuple>::value,
+ bool
+ >::type = false
>
_LIBCPP_INLINE_VISIBILITY
tuple(_Tuple&& __t)
: base_(_VSTD::forward<_Tuple>(__t)) {}
+ template <class _Tuple,
+ typename enable_if
+ <
+ __tuple_constructible<_Tuple, tuple>::value &&
+ !__tuple_convertible<_Tuple, tuple>::value,
+ bool
+ >::type = false
+ >
+ _LIBCPP_INLINE_VISIBILITY
+ explicit
+ tuple(_Tuple&& __t)
+ : base_(_VSTD::forward<_Tuple>(__t)) {}
+
template <class _Alloc, class _Tuple,
class = typename enable_if
<
Modified: libcxx/trunk/test/utilities/tuple/tuple.tuple/tuple.cnstr/UTypes.fail.cpp
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/utilities/tuple/tuple.tuple/tuple.cnstr/UTypes.fail.cpp?rev=153855&r1=153854&r2=153855&view=diff
==============================================================================
--- libcxx/trunk/test/utilities/tuple/tuple.tuple/tuple.cnstr/UTypes.fail.cpp (original)
+++ libcxx/trunk/test/utilities/tuple/tuple.tuple/tuple.cnstr/UTypes.fail.cpp Sun Apr 1 18:10:42 2012
@@ -14,14 +14,36 @@
// template <class... UTypes>
// explicit tuple(UTypes&&... u);
+/*
+ This is testing an extension whereby only Types having an explicit conversion
+ from UTypes are bound by the explicit tuple constructor.
+*/
+
#include <tuple>
#include <cassert>
-#include "../MoveOnly.h"
+class MoveOnly
+{
+ MoveOnly(const MoveOnly&);
+ MoveOnly& operator=(const MoveOnly&);
+
+ int data_;
+public:
+ explicit MoveOnly(int data = 1) : data_(data) {}
+ MoveOnly(MoveOnly&& x)
+ : data_(x.data_) {x.data_ = 0;}
+ MoveOnly& operator=(MoveOnly&& x)
+ {data_ = x.data_; x.data_ = 0; return *this;}
+
+ int get() const {return data_;}
+
+ bool operator==(const MoveOnly& x) const {return data_ == x.data_;}
+ bool operator< (const MoveOnly& x) const {return data_ < x.data_;}
+};
int main()
{
{
- std::tuple<MoveOnly> t = MoveOnly(0);
+ std::tuple<MoveOnly> t = 1;
}
}
Modified: libcxx/trunk/test/utilities/tuple/tuple.tuple/tuple.cnstr/const_Types.fail.cpp
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/utilities/tuple/tuple.tuple/tuple.cnstr/const_Types.fail.cpp?rev=153855&r1=153854&r2=153855&view=diff
==============================================================================
--- libcxx/trunk/test/utilities/tuple/tuple.tuple/tuple.cnstr/const_Types.fail.cpp (original)
+++ libcxx/trunk/test/utilities/tuple/tuple.tuple/tuple.cnstr/const_Types.fail.cpp Sun Apr 1 18:10:42 2012
@@ -20,7 +20,6 @@
int main()
{
{
- std::tuple<int> t = 2;
- assert(std::get<0>(t) == 2);
+ std::tuple<int*> t = 0;
}
}
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