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LWG3476: thread and jthread constructors require that the parameters be move-constructible but never move construct the parameters #104307
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Thanks @mleleszi!
I have some thoughts:
- For all of
async,jthread, andthread, we should add test cases. - For
thread, I think these Mandates are already implicitly imposed by usingtuple. - For
async, I believe we need to refactor internal functions to perfect-forward arguments wherever needed.
Such a class can be used. In tests, we can use a cv-unqualified
test_classlvalue as an argument.struct test_class { test_class() = default; test_class(test_class&) = default; test_class(const test_class&) = delete; };
- For all of
- marked [libc++] Possibly redundant auto-cast in
async#143828 as a duplicate of this issueon Dec 22, 2025 Thanks for the pointers!
For
thread, would it still be worth adding the mandates explicitly? Or you usually don't do that if they're implicitly imposed.I think additional explicit
static_assertwould be a bit useful, as the error messages fromtupleconstructors are usually messy.Reacted by Marcell Leleszi- added a commit that references this issue
on Dec 25, 2025 - moved this from Todo to Done in libc++ Standards Conformance
on Dec 25, 2025 - added a commit that references this issue
on Dec 25, 2025 - added a commit that references this issue
on Jan 6, 2026 - added a commit that references this issue
on Jun 14, 2026
Link: https://wg21.link/LWG3476