Re: [PATCH v2] gdb: Use C++11 std::chrono

[Simon Marchi <simon dot marchi at polymtl dot ca>]

On 2016-11-22 21:17, Pedro Alves wrote:
> I kept them (from v1) for type-safety: it makes it impossible to swap
> the arguments to this new now() method by mistake, or compare old
> system time with new user time by mistake.  E.g.:
>
> /usr/include/c++/5.3.1/chrono:650:7: note: candidate: template<class
> _Clock, class _Dur1, class _Dur2> constexpr typename
> std::common_type<_Duration1, _Duration2>::type
> std::chrono::operator-(const std::chrono::time_point<_Clock,
> _Duration1>&, const std::chrono::time_point<_Clock, _Duration2>&)
>        operator-(const time_point<_Clock, _Dur1>& __lhs,
>        ^
> /usr/include/c++/5.3.1/chrono:650:7: note:   template argument
> deduction/substitution failed:
> src/gdb/mi/mi-main.c:2493:48: note:   deduced conflicting types for
> parameter ‘_Clock’ (‘system_cpu_time_clock’ and ‘user_cpu_time_clock’)
>    duration<double> utime = end->stime - start->utime;
>                                                 ^
>
> Would you still prefer I remove those?

That sounds useful, I'm convinced.

> > Unrelated: for future work, it looks like an std::priority_queue would
> > be a nice match for timer_list.
>
> Maybe, but we'd need to inherit from it in order to be able to
> delete timers that are not at the top of the heap.  A set or
> multiset would be other options.

You're right:

https://stackoverflow.com/questions/19467485/c-priority-queue-removing-element-not-at-top

Perhaps that's a bit too much for the amount of timers we usually have 
though...