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Re: debug extension overhead
Benjamin Kosnik <bkoz@redhat.com> writes:
>
> > Have you considered adding a knob that would turn on a subset of
> > _GLIBCXX_DEBUG checks that have lower overhead, e.g., guaranteed
> > constant factor? Some users are giving up on it due to high overhead
> > in certain cases, but they could benefit from cheap checks, such as
> > vector subscript checks.
>
> Hmm. The idea was that for fine-grained checks, one would just select
> the debug extension on a per-header basis, instead of using
> _GLIBCXX_DEBUG. Ie, including debug/vector and
> using __gnu_debug::vector if all you want is vector subscript checks.
Does this work in practice? I haven't tried, but:
... you can only link code compiled with debug mode and code compiled
without debug mode if no instantiation of a container is passed
between the two translation units. [1]
implies that doing so in a large application would be very difficult,
unless you didn't use containers as part of your interfaces.
-tom
[1] http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt12ch30s03.html#debug_mode.using.specific