Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.93%. Comparing base (582200a) to head (76862dc).
⚠️ Report is 1 commits behind head on devel.

@@            Coverage Diff             @@
##            devel    #3005      +/-   ##
==========================================
- Coverage   90.97%   90.93%   -0.03%     
==========================================
  Files         201      201              
  Lines        8681     8681              
==========================================
- Hits         7897     7894       -3     
- Misses        784      787       +3     

Thanks, this is useful change.

To avoid splitting the discussion into two places, I am gonna comment on the issue here instead.

• The reproducer does not compile, you cannot have || or && in assertion.
• The issue is real. The lifetime of the lambda that creates the generator ends before the generator's lifetime does, which means that if the generator takes a reference to its capture (the way filter currently does with the predicate), it will be a dead reference.
• The test in this PR is a bit lacking. The behaviour you've observed was caused by the difference in stack layout/usage between difference compilers and configurations. A better test would be to create the generator in a function, and then call different function between calls to next, to overwrite the stack memory.