Summary:
Currently parts of the SFINAE on tuples default constructor always gets evaluated even when the default constructor is never called or instantiated. This can cause a hard compile error when a tuple is created with types that do not have a default constructor. Below is a self contained example using a pair like class. This code will not compile but probably should.
```
#include <type_traits>
template <class T>
struct IllFormedDefaultImp {
IllFormedDefaultImp(T x) : value(x) {}
constexpr IllFormedDefaultImp() {}
T value;
};
typedef IllFormedDefaultImp<int &> IllFormedDefault;
template <class T, class U>
struct pair
{
template <bool Dummy = true,
class = typename std::enable_if<
std::is_default_constructible<T>::value
&& std::is_default_constructible<U>::value
&& Dummy>::type
>
constexpr pair() : first(), second() {}
pair(T const & t, U const & u) : first(t), second(u) {}
T first;
U second;
};
int main()
{
int x = 1;
IllFormedDefault v(x);
pair<IllFormedDefault, IllFormedDefault> p(v, v);
}
```
One way to fix this is to use `Dummy` in a more involved way in the constructor SFINAE. The following patch fixes these sorts of hard compile errors for tuple.
Reviewers: mclow.lists, rsmith, K-ballo, EricWF
Reviewed By: EricWF
Subscribers: ldionne, cfe-commits
Differential Revision: http://reviews.llvm.org/D7569
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@230120 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: No declaration for the type `tuple` is given in c++03 or c++98 modes. Mark all tests that use the actual `tuple` type as UNSUPPORTED.
Reviewers: jroelofs, mclow.lists, danalbert
Reviewed By: danalbert
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D5956
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@229808 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This patch introduces some black magic to detect const and volatile qualified function types such as `void () const`.
The patch works in the following way:
We first rule out any type that satisfies on of the following. These restrictions are important so that the test below works properly.
* `is_class<_Tp>::value`
* `is_union<_Tp>::value`
* `is_void<_Tp>::value`
* `is_reference<_Tp>::value`
* `__is_nullptr_t<_Tp>::value`
If none of the above is true we perform overload resolution on `__source<_Tp>(0)` to determine the return type.
* If `_Tp&` is well-formed we select `_Tp& __source(int)`. `_Tp&` is only ill formed for cv void types and cv/ref qualified function types.
* Otherwise we select `__dummy_type __source(...)`. Since we know `_Tp` cannot be void then it must be a function type.
let `R` be the returned from `__source<_Tp>(0)`.
We perform overload resolution on `__test<_Tp>(R)`.
* If `R` is `__dummy_type` we call `true_type __test(__dummy_type)`.
* if `R` is `_Tp&` and `_Tp&` decays to `_Tp*` we call `true_type __test(_Tp*)`. Only references to function types decay to a pointer of the same type.
* In all other cases we call `false_type __test(...)`.
`__source<_Tp>(0)` will try and form `_Tp&` in the return type. if `_Tp&` is not well formed the return type of `__source<_Tp>(0)` will be dummy type. `_Tp&` is only ill-formed for cv/ref qualified function types (and void which is dealt with elsewhere).
This fixes PR20084 - http://llvm.org/bugs/show_bug.cgi?id=20084
Reviewers: rsmith, K-ballo, mclow.lists
Reviewed By: mclow.lists
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D7573
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@229696 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
The bug can be found here: http://llvm.org/bugs/show_bug.cgi?id=22468
`__invoke_void_return_wrapper` is needed to properly handle calling a function that returns a value but where the std::function return type is void. Without this '-Wsystem-headers' will cause `function::operator()(...)` to not compile.
Reviewers: eugenis, K-ballo, mclow.lists
Reviewed By: mclow.lists
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D7444
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@228705 91177308-0d34-0410-b5e6-96231b3b80d8
The SFINAE on the function __mu(Fn, Args...) that evaluates nested bind
expressions always tries to deduce the return type for Fn(Args...) even when Fn
is not a nested bind expression. This can cause hard compile errors when the
instantation of Fn(Args...) is ill-formed. This patch prevents the instantation
of __invoke_of<Fn, Args...> unless Fn is actually a bind expression.
Bug reportand patch from Michel Morin.
http://llvm.org/bugs/show_bug.cgi?id=22003
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@224753 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
MSAN and ASAN also replace new/delete which leads to a link error in these tests. Currently they are unsupported but I think it would be useful if these tests could run with sanitizers.
This patch creates a support header that consolidates the new/delete replacement functionality and checking.
When we are using sanitizers new and delete are no longer replaced and the checks always return true.
Reviewers: mclow.lists, danalbert, jroelofs, EricWF
Reviewed By: EricWF
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D6562
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@224741 91177308-0d34-0410-b5e6-96231b3b80d8
