visual-cpp-templates.cpp

// make templates work in Visual Studio
// xref: https://github.com/measurement-kit/measurement-kit/pull/1536

#include <stdlib.h>
#include <time.h>

#include <iostream>

// experiment with several combinations of modifiers
#if 1
#define SI static inline
#else
#define SI // nothing
#endif

namespace mkp {

template <decltype(::timespec_get) func>
double MockableNow() noexcept {
    timespec ts{};
    if (func(&ts, TIME_UTC) != TIME_UTC) {
        abort();
    }
    return ts.tv_sec + (double)ts.tv_nsec / 1'000'000'000;
}

SI double Now() noexcept { return MockableNow<::timespec_get>(); }

template <decltype(Now) func>
double MockableMakeDeadline(double timeout) noexcept {
    return func() + timeout;
}

SI double MakeDeadline(double timeout) noexcept {
    return MockableMakeDeadline<Now>(timeout);
}

} // namespace mkp

int main() {
    std::clog << mkp::MakeDeadline(10.0) << "\n";
}