`__wrap_iter` is currently only constexpr if it's not a debug built, but it isn't used in a constexpr context currently. Making it always constexpr and disabling the debugging utilities at constant evaluation is more usful since it has to be always constexpr to be used in a constexpr context.
Reviewed By: ldionne, #libc
Spies: libcxx-commits
Differential Revision: https://reviews.llvm.org/D114733
This addresses the usage of `operator&` in `<vector>`.
I now added tests for the current offending cases. I wonder whether it
would be better to add one addressof test per directory and test all
possible violations. Also to guard against possible future errors?
(Note there are still more headers with the same issue.)
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D111961
Instead of overloading `__to_address`, let's specialize `pointer_traits`.
Function overloads need to be in scope at the point where they're called,
whereas template specializations do not. (User code can provide pointer_traits
specializations to be used by already-included library code, so obviously
`__wrap_iter` can do the same.)
`pointer_traits<__wrap_iter<It>>` cannot provide `pointer_to`, because
you generally cannot create a `__wrap_iter` without also knowing the
identity of the container into which you're trying to create an iterator.
I believe this is OK; contiguous iterators are required to provide
`to_address` but *not* necessarily `pointer_to`.
Differential Revision: https://reviews.llvm.org/D110198
It turns out that D105040 broke `std::rel_ops`; we actually do need
both a one-template-parameter and a two-template-parameter version of
all the comparison operators, because if we have only the heterogeneous
two-parameter version, then `x > x` is ambiguous:
template<class T, class U> int f(S<T>, S<U>) { return 1; }
template<class T> int f(T, T) { return 2; } // rel_ops
S<int> s; f(s,s); // ambiguous between #1 and #2
Adding the one-template-parameter version fixes the ambiguity:
template<class T, class U> int f(S<T>, S<U>) { return 1; }
template<class T> int f(T, T) { return 2; } // rel_ops
template<class T> int f(S<T>, S<T>) { return 3; }
S<int> s; f(s,s); // #3 beats both #1 and #2
We have the same problem with `reverse_iterator` as with `__wrap_iter`.
But so do libstdc++ and Microsoft, so we're not going to worry about it.
Differential Revision: https://reviews.llvm.org/D105894
Nikolas Klauser