D4451: Fix copy/move issues casude by __tuple_leafs's converting constructor
llvm-svn: 213888
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 567bb79bf2f414bd93162383b368985580725b13
diff --git a/include/__tuple b/include/__tuple
index de35cb8..ee5b916 100644
--- a/include/__tuple
+++ b/include/__tuple
@@ -27,6 +27,32 @@
_LIBCPP_BEGIN_NAMESPACE_STD
+// __lazy_and
+
+template <bool _Last, class ..._Preds>
+struct __lazy_and_impl;
+
+template <class ..._Preds>
+struct __lazy_and_impl<false, _Preds...> : false_type {};
+
+template <>
+struct __lazy_and_impl<true> : true_type {};
+
+template <class _Pred>
+struct __lazy_and_impl<true, _Pred> : integral_constant<bool, _Pred::type::value> {};
+
+template <class _Hp, class ..._Tp>
+struct __lazy_and_impl<true, _Hp, _Tp...> : __lazy_and_impl<_Hp::type::value, _Tp...> {};
+
+template <class _P1, class ..._Pr>
+struct __lazy_and : __lazy_and_impl<_P1::type::value, _Pr...> {};
+
+// __lazy_not
+
+template <class _Pred>
+struct __lazy_not : integral_constant<bool, !_Pred::type::value> {};
+
+
template <class _Tp> class _LIBCPP_TYPE_VIS_ONLY tuple_size;
template <class _Tp>
diff --git a/include/tuple b/include/tuple
index e98ae72..c3fdd40 100644
--- a/include/tuple
+++ b/include/tuple
@@ -210,7 +210,13 @@
"Attempted to default construct a reference element in a tuple");}
template <class _Tp,
- class = typename enable_if<is_constructible<_Hp, _Tp>::value>::type>
+ class = typename enable_if<
+ __lazy_and<
+ __lazy_not<is_same<typename decay<_Tp>::type, __tuple_leaf>>
+ , is_constructible<_Hp, _Tp>
+ >::value
+ >::type
+ >
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
explicit __tuple_leaf(_Tp&& __t) _NOEXCEPT_((is_nothrow_constructible<_Hp, _Tp>::value))
: value(_VSTD::forward<_Tp>(__t))
@@ -316,7 +322,13 @@
: _Hp(__a) {}
template <class _Tp,
- class = typename enable_if<is_constructible<_Hp, _Tp>::value>::type>
+ class = typename enable_if<
+ __lazy_and<
+ __lazy_not<is_same<typename decay<_Tp>::type, __tuple_leaf>>
+ , is_constructible<_Hp, _Tp>
+ >::value
+ >::type
+ >
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
explicit __tuple_leaf(_Tp&& __t) _NOEXCEPT_((is_nothrow_constructible<_Hp, _Tp>::value))
: _Hp(_VSTD::forward<_Tp>(__t)) {}
@@ -336,6 +348,9 @@
explicit __tuple_leaf(integral_constant<int, 2>, const _Alloc& __a, _Tp&& __t)
: _Hp(_VSTD::forward<_Tp>(__t), __a) {}
+ __tuple_leaf(__tuple_leaf const &) = default;
+ __tuple_leaf(__tuple_leaf &&) = default;
+
template <class _Tp>
_LIBCPP_INLINE_VISIBILITY
__tuple_leaf&
diff --git a/test/utilities/tuple/tuple.tuple/tuple.cnstr/const_Types.pass.cpp b/test/utilities/tuple/tuple.tuple/tuple.cnstr/const_Types.pass.cpp
index 04cb3d5..ca53cd3 100644
--- a/test/utilities/tuple/tuple.tuple/tuple.cnstr/const_Types.pass.cpp
+++ b/test/utilities/tuple/tuple.tuple/tuple.cnstr/const_Types.pass.cpp
@@ -17,6 +17,40 @@
#include <string>
#include <cassert>
+
+template <class ...>
+struct never {
+ enum { value = 0 };
+};
+
+struct NoValueCtor
+{
+ NoValueCtor() : id(++count) {}
+ NoValueCtor(NoValueCtor const & other) : id(other.id) { ++count; }
+
+ // The constexpr is required to make is_constructible instantiate this template.
+ // The explicit is needed to test-around a similar bug with is_convertible.
+ template <class T>
+ constexpr explicit NoValueCtor(T)
+ { static_assert(never<T>::value, "This should not be instantiated"); }
+
+ static int count;
+ int id;
+};
+
+int NoValueCtor::count = 0;
+
+
+struct NoValueCtorEmpty
+{
+ NoValueCtorEmpty() {}
+ NoValueCtorEmpty(NoValueCtorEmpty const &) {}
+
+ template <class T>
+ constexpr explicit NoValueCtorEmpty(T)
+ { static_assert(never<T>::value, "This should not be instantiated"); }
+};
+
int main()
{
{
@@ -56,6 +90,23 @@
assert(std::get<1>(t) == nullptr);
assert(std::get<2>(t) == "text");
}
+ // __tuple_leaf<T> uses is_constructible<T, U> to disable its explicit converting
+ // constructor overload __tuple_leaf(U &&). Evaluating is_constructible can cause a compile error.
+ // This overload is evaluated when __tuple_leafs copy or move ctor is called.
+ // This checks that is_constructible is not evaluated when U == __tuple_leaf.
+ {
+ std::tuple<int, NoValueCtor, int, int> t(1, NoValueCtor(), 2, 3);
+ assert(std::get<0>(t) == 1);
+ assert(std::get<1>(t).id == 1);
+ assert(std::get<2>(t) == 2);
+ assert(std::get<3>(t) == 3);
+ }
+ {
+ std::tuple<int, NoValueCtorEmpty, int, int> t(1, NoValueCtorEmpty(), 2, 3);
+ assert(std::get<0>(t) == 1);
+ assert(std::get<2>(t) == 2);
+ assert(std::get<3>(t) == 3);
+ }
// extensions
{
std::tuple<int, char*, std::string> t(2);
diff --git a/test/utilities/tuple/tuple.tuple/tuple.cnstr/move.pass.cpp b/test/utilities/tuple/tuple.tuple/tuple.cnstr/move.pass.cpp
index 41e4b66..8dc7d21 100644
--- a/test/utilities/tuple/tuple.tuple/tuple.cnstr/move.pass.cpp
+++ b/test/utilities/tuple/tuple.tuple/tuple.cnstr/move.pass.cpp
@@ -18,6 +18,18 @@
#include "../MoveOnly.h"
+struct ConstructsWithTupleLeaf
+{
+ ConstructsWithTupleLeaf() {}
+
+ ConstructsWithTupleLeaf(ConstructsWithTupleLeaf const &) { assert(false); }
+ ConstructsWithTupleLeaf(ConstructsWithTupleLeaf &&) {}
+
+ template <class T>
+ ConstructsWithTupleLeaf(T t)
+ { assert(false); }
+};
+
int main()
{
{
@@ -46,4 +58,12 @@
assert(std::get<1>(t) == 1);
assert(std::get<2>(t) == 2);
}
+ // A bug in tuple caused __tuple_leaf to use its explicit converting constructor
+ // as its move constructor. This tests that ConstructsWithTupleLeaf is not called
+ // (w/ __tuple_leaf)
+ {
+ typedef std::tuple<ConstructsWithTupleLeaf> d_t;
+ d_t d((ConstructsWithTupleLeaf()));
+ d_t d2(static_cast<d_t &&>(d));
+ }
}
diff --git a/test/utilities/tuple/tuple.tuple/tuple.elem/tuple.by.type1.fail.cpp b/test/utilities/tuple/tuple.tuple/tuple.elem/tuple.by.type1.fail.cpp
index ec63a39..d955456 100644
--- a/test/utilities/tuple/tuple.tuple/tuple.elem/tuple.by.type1.fail.cpp
+++ b/test/utilities/tuple/tuple.tuple/tuple.elem/tuple.by.type1.fail.cpp
@@ -18,7 +18,7 @@
#if _LIBCPP_STD_VER > 11
typedef std::complex<float> cf;
auto t1 = std::make_tuple<int, std::string> ( 42, "Hi" );
- assert ( std::get<cf>(t1) == cf {1,2} ); // no such type
+ assert (( std::get<cf>(t1) == cf {1,2} )); // no such type
#else
#error
#endif
diff --git a/test/utilities/utility/pairs/pair.astuple/pairs.by.type1.fail.cpp b/test/utilities/utility/pairs/pair.astuple/pairs.by.type1.fail.cpp
index 1c01ed7..27194ef 100644
--- a/test/utilities/utility/pairs/pair.astuple/pairs.by.type1.fail.cpp
+++ b/test/utilities/utility/pairs/pair.astuple/pairs.by.type1.fail.cpp
@@ -17,7 +17,7 @@
#if _LIBCPP_STD_VER > 11
typedef std::complex<float> cf;
auto t1 = std::make_pair<int, double> ( 42, 3.4 );
- assert ( std::get<cf>(t1) == cf {1,2} ); // no such type
+ assert (( std::get<cf>(t1) == cf {1,2} )); // no such type
#else
#error
#endif