test: add scheduler_concept regression guard for all stdexec schedulers - #2257
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ericniebler merged 2 commits intoSep 16, 2026
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Per [exec.sched], scheduler types should define a nested scheduler_concept alias derived from scheduler_tag. PR NVIDIA#2256 (issue NVIDIA#2134) added the missing aliases; this adds compile-time guards so the requirement cannot regress. - New test/exec/test_scheduler_concept.cpp statically asserts the alias and scheduler<> satisfaction for the always-available schedulers: inline, run_loop, task_scheduler, parallel, static_thread_pool, thread_pool_base (CRTP), timed_thread, trampoline, and the internal reschedule scheduler. - Gated schedulers are asserted in their existing gated test files: io_uring, windows_thread_pool, libdispatch, and the nvexec stream and multi-GPU stream schedulers. Generated with Codebuff Co-Authored-By: Codebuff <noreply@codebuff.com>
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Hi @ericniebler — small test-only follow-up to #2256: compile-time guards so the scheduler_concept alias from #2134 can't silently regress. Could you /ok to test when you get a chance? Thanks! |
ericniebler
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Sep 15, 2026
…ng-format 🤖 Generated with Codebuff Co-Authored-By: Codebuff <noreply@codebuff.com>
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Pushed a one-line clang-format fix (0f216e4) — the style check should be green now, but the new workflow run is sitting in "awaiting maintainer approval". Could you approve it when you get a chance? Thanks! |
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/ok to test 0f216e4 |
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Follow-up to #2256.
While working on #2134 I noticed nothing actually stops this from coming back — a
new scheduler can forget the
scheduler_conceptalias and users end up with thesame confusing
no viable overloaded '='error insideexec::taskagain. So thisPR adds a small compile-time guard, test-only, that fails to build if any
scheduler in stdexec drops the alias.
What's here:
test/exec/test_scheduler_concept.cpp(new): statically checks that thealways-built schedulers — inline, run_loop, task_scheduler, parallel,
static_thread_pool, thread_pool_base-derived pools, timed_thread, trampoline,
and reschedule's internal scheduler — define the alias and satisfy
scheduler<>.multi-GPU stream) are asserted in their existing gated test files, so no extra
CMake plumbing is needed on other platforms.
Verification:
test.exec— 3417 assertions / 362 cases pass (Release, Apple Clang 21).Happy to move or restructure this if there's a better home for the guard.