[libcxx-commits] [libcxx] [libc++] Throw future_error in future.get() (PR #179409)

[Louis Dionne via libcxx-commits]

https://github.com/ldionne requested changes to this pull request.

The Standard reference to the recommended practice is https://eel.is/c++draft/futures#unique.future-3.

Can you please add a test for this behavior? The test should go in `libcxx/test/std/thread/futures/futures.unique_future/get.pass.cpp` and should be guarded by `#if defined(_LIBCPP_VERSION)` since this is libc++ specific behavior.

https://github.com/llvm/llvm-project/pull/179409