[boost] [Boost.Timer] Why timer doesn't have a specific windows version using QueryPerformanceCounter() and QueryPerformanceFrequency()?

Hi, Boost.Timer is based on the C function clock(). On windows, this function gives a precision of 1 millisecond only as CLOCKS_PER_SEC is equal to 1000. Why Boost.Timer doesn't use for windows QueryPerformanceCounter() and QueryPerformanceFrequency()? These functions give a precision around 2 microseconds. Daniel.