Fix non-conformance it `std::tuple`.
Previously we implemented all one trillion tuple-like constructors using
a single generic overload. This worked fairly well, except that it
differed in behavior from the standard version because it didn't
consider both T&& and T const&. This was observable for certain
types.
This patch addresses that issue by splitting the generic constructor
in two. We now provide both T&& and T const& versions of the
tuple-like constructors (sort of).
llvm-svn: 365973
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 882fdf68b74d3199cb84b062709b702ed610f547
diff --git a/include/tuple b/include/tuple
index de30e86..031d25a 100644
--- a/include/tuple
+++ b/include/tuple
@@ -601,6 +601,25 @@
}
};
+ template <class _Tuple, bool _DisableIfLValue>
+ using _EnableImplicitTupleLikeConstructor = _EnableIf<
+ _CheckTupleLikeConstructor<
+ __tuple_like_with_size<_Tuple, sizeof...(_Tp)>::value
+ && !_PackExpandsToThisTuple<_Tuple>::value
+ && (!is_lvalue_reference<_Tuple>::value || !_DisableIfLValue)
+ >::template __enable_implicit<_Tuple>(),
+ bool
+ >;
+
+ template <class _Tuple, bool _DisableIfLValue>
+ using _EnableExplicitTupleLikeConstructor = _EnableIf<
+ _CheckTupleLikeConstructor<
+ __tuple_like_with_size<_Tuple, sizeof...(_Tp)>::value
+ && !_PackExpandsToThisTuple<_Tuple>::value
+ && (!is_lvalue_reference<_Tuple>::value || !_DisableIfLValue)
+ >::template __enable_explicit<_Tuple>(),
+ bool
+ >;
template <size_t _Jp, class ..._Up> friend _LIBCPP_CONSTEXPR_AFTER_CXX11
typename tuple_element<_Jp, tuple<_Up...> >::type& get(tuple<_Up...>&) _NOEXCEPT;
template <size_t _Jp, class ..._Up> friend _LIBCPP_CONSTEXPR_AFTER_CXX11
@@ -815,35 +834,27 @@
typename __make_tuple_types<tuple, sizeof...(_Tp), sizeof...(_Up)>::type(),
_VSTD::forward<_Up>(__u)...) {}
- template <class _Tuple,
- typename enable_if
- <
- _CheckTupleLikeConstructor<
- __tuple_like_with_size<_Tuple, sizeof...(_Tp)>::value
- && !_PackExpandsToThisTuple<_Tuple>::value
- >::template __enable_implicit<_Tuple>(),
- bool
- >::type = false
- >
+ template <class _Tuple, _EnableImplicitTupleLikeConstructor<_Tuple, true> = false>
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
tuple(_Tuple&& __t) _NOEXCEPT_((is_nothrow_constructible<_BaseT, _Tuple>::value))
: __base_(_VSTD::forward<_Tuple>(__t)) {}
- template <class _Tuple,
- typename enable_if
- <
- _CheckTupleLikeConstructor<
- __tuple_like_with_size<_Tuple, sizeof...(_Tp)>::value
- && !_PackExpandsToThisTuple<_Tuple>::value
- >::template __enable_explicit<_Tuple>(),
- bool
- >::type = false
- >
+ template <class _Tuple, _EnableImplicitTupleLikeConstructor<const _Tuple&, false> = false>
+ _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+ tuple(const _Tuple& __t) _NOEXCEPT_((is_nothrow_constructible<_BaseT, const _Tuple&>::value))
+ : __base_(__t) {}
+ template <class _Tuple, _EnableExplicitTupleLikeConstructor<_Tuple, true> = false>
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
explicit
tuple(_Tuple&& __t) _NOEXCEPT_((is_nothrow_constructible<_BaseT, _Tuple>::value))
: __base_(_VSTD::forward<_Tuple>(__t)) {}
+ template <class _Tuple, _EnableExplicitTupleLikeConstructor<const _Tuple&, false> = false>
+ _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+ explicit
+ tuple(const _Tuple& __t) _NOEXCEPT_((is_nothrow_constructible<_BaseT, const _Tuple&>::value))
+ : __base_(__t) {}
+
template <class _Alloc, class _Tuple,
typename enable_if
<