https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98000
--- Comment #5 from ishikawa,chiaki <ishikawa at yk dot rim.or.jp> --- (In reply to Martin Liška from comment #3) > Thank you for the report, it's very likely a different issue. > I'm reducing that right now.. You are very welcome and thank you for the reduction to simpler case in comment 4. I used to work on compilers, interpreters, assemblers, etc. many moons ago, but the current complexity of g++-10, and for that matter C++ and complex software like mozilla thunderbird, is beyond a mere user like myself, especially trying to reduce the memory usage by means of "clone on demand" sounds a very hairy approach (hairy as in the old Hacker's dictionary meaning). I AM impressed. Thank you again. (I would have used "Happy Hacking" in the old days, but nowadays, hacking only seems to be taken to carry a very negative sense. Sad.)