Hi, On Mon, 23 Oct 2017, Richard Biener wrote:
> I guess so. But we have to make gdb happy as well. It really depends how > much each TU grows with the extra (unneeded) include grows in C++11 and > C++04 mode. The c++ headers unconditionally included from system.h, with: % echo '#include <$name>' | g++-7 -E -x c++ - | wc -l new: 3564 cstring: 533 utility: 3623 memory: 28066 compile time: % echo -e '#include <$name>\nint i;' | time g++-7 -c -x c++ - new: 0:00.06elapsed, 17060maxresident, 0major+3709minor cstring: 0:00.03elapsed, 13524maxresident, 0major+3075minor utility: 0:00.05elapsed, 16952maxresident, 0major+3776minor memory: 0:00.25elapsed, 40356maxresident, 0major+9764minor Hence, <memory> is not cheap at all, including it unconditionally from system.h when it isn't actually used by many things doesn't seem a good idea. Ciao, Michael.
