that's pity - because I've the problem to achieve your request regarding to make the
algorithm interface accepting every time_point provided by or derived from boost.chrono.

the interface 'algorithm' has pure virtual functions only, so I can't use templated functions

(e.g. make clock-type an template argument).

another solution would be making the interface class itself to an template (using the clock-type

as template arg.). but this breaks the API because every class (even fiber itself) of the lib

depended on the template arg of algorithm. this is caused by the fact that the scheduler

 implementation (derived from interface 'algorithm') is accessed through a pointer of type

'algorithm'.

for instance mutex::lock() suspends a fiber if the mutex is already locked by another fiber.

suspending is done by calling algorithm::wait(). this is done via detail::scheduler::instance()->wait();

as you see - scheduler::instance() returns the pointer to algorithm (stored inside a static thread_specific_ptr).

thus scheduler must know the template argument of algorithm  and therefore mutex needs too.

As you see all class would be affected and this makes the API itself unusable.

do you have any other idea to get your request from the review working?

or might it acceptable to use on clock-type from boost.chrono?