unique_lock_ref

unique_lock_ref.cc

#include <iostream>
#include <mutex>

template <typename mutex>
struct unique_lock_ref {
    unique_lock_ref(const std::unique_lock<mutex>& lh) {
        if (!lh) {
            throw std::logic_error("Cannot instantiate a unique_lock_ref "
                                   "with an unlocked unique_lock");
        }
    }
};

float my_locked_func(unique_lock_ref<std::mutex> r, int some_other_arg, float another_arg) {
    return some_other_arg + another_arg;
}

std::mutex m;

int main(int argc, char** argv) {
    std::unique_lock<std::mutex> lh(m);
    my_locked_func(lh, 3, 5.6);
    lh.unlock();
    my_locked_func(lh, 4, 5.2); // throws logic_error
}