Fix for PR 19616: 'tuple_cat of nested tuples fails in noexcept specification'. Thanks to Louis Dionne for the fix.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@219243 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Marshall Clow 2014-10-07 21:42:12 +00:00
parent 4c88839716
commit df9722ecf1
3 changed files with 43 additions and 7 deletions

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@ -2888,29 +2888,38 @@ struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_constructible
#if __has_feature(cxx_noexcept) || (_GNUC_VER >= 407 && __cplusplus >= 201103L)
template <bool, class _Tp, class... _Args> struct __libcpp_is_nothrow_constructible;
template <bool, bool, class _Tp, class... _Args> struct __libcpp_is_nothrow_constructible;
template <class _Tp, class... _Args>
struct __libcpp_is_nothrow_constructible<true, _Tp, _Args...>
struct __libcpp_is_nothrow_constructible</*is constructible*/true, /*is reference*/false, _Tp, _Args...>
: public integral_constant<bool, noexcept(_Tp(declval<_Args>()...))>
{
};
template <class _Tp, class... _Args>
struct __libcpp_is_nothrow_constructible<false, _Tp, _Args...>
template <class _Tp>
void __implicit_conversion_to(_Tp) noexcept { }
template <class _Tp, class _Arg>
struct __libcpp_is_nothrow_constructible</*is constructible*/true, /*is reference*/true, _Tp, _Arg>
: public integral_constant<bool, noexcept(__implicit_conversion_to<_Tp>(declval<_Arg>()))>
{
};
template <class _Tp, bool _IsReference, class... _Args>
struct __libcpp_is_nothrow_constructible</*is constructible*/false, _IsReference, _Tp, _Args...>
: public false_type
{
};
template <class _Tp, class... _Args>
struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_constructible
: __libcpp_is_nothrow_constructible<is_constructible<_Tp, _Args...>::value, _Tp, _Args...>
: __libcpp_is_nothrow_constructible<is_constructible<_Tp, _Args...>::value, is_reference<_Tp>::value, _Tp, _Args...>
{
};
template <class _Tp, size_t _Ns>
struct _LIBCPP_TYPE_VIS_ONLY is_nothrow_constructible<_Tp[_Ns]>
: __libcpp_is_nothrow_constructible<is_constructible<_Tp>::value, _Tp>
: __libcpp_is_nothrow_constructible<is_constructible<_Tp>::value, is_reference<_Tp>::value, _Tp>
{
};

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@ -76,15 +76,28 @@ struct C
void operator=(C&); // not const
};
#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
struct Tuple {
Tuple(Empty&&) noexcept {}
};
#endif
int main()
{
test_is_nothrow_constructible<int> ();
test_is_nothrow_constructible<int, const int&> ();
test_is_nothrow_constructible<Empty> ();
test_is_nothrow_constructible<Empty, const Empty&> ();
#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
test_is_nothrow_constructible<Tuple &&, Empty> (); // See bug #19616.
#endif
test_is_not_nothrow_constructible<A, int> ();
test_is_not_nothrow_constructible<A, int, double> ();
test_is_not_nothrow_constructible<A> ();
test_is_not_nothrow_constructible<C> ();
#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
static_assert(!std::is_constructible<Tuple&, Empty>::value, "");
test_is_not_nothrow_constructible<Tuple &, Empty> (); // See bug #19616.
#endif
}

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@ -213,4 +213,18 @@ int main()
assert(std::get<3>(t3) == 4);
assert(std::get<4>(t3) == 5);
}
{
// See bug #19616.
auto t1 = std::tuple_cat(
std::make_tuple(std::make_tuple(1)),
std::make_tuple()
);
assert(t1 == std::make_tuple(std::make_tuple(1)));
auto t2 = std::tuple_cat(
std::make_tuple(std::make_tuple(1)),
std::make_tuple(std::make_tuple(2))
);
assert(t2 == std::make_tuple(std::make_tuple(1), std::make_tuple(2)));
}
}