On Fri, 2 Jun 2023 at 10:30, Alexandre Oliva via Libstdc++ <
libstdc++@gcc.gnu.org> wrote:

>
> ISTM that rtems is missing some of the math.h functions expected by
> libstdc++, but also that even those that are present are not visible in
> namespace ::std::, where the macros reasonably expect to find them.  Is
> this known?  Should I file a PR about it?
>

That looks like https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109818

We only import the C99 <math.h> functions into namespace std when the
target libc supports all of them.