I want to free my code from the 5 std::mutex::unlock calls per function in favor of std::lock_guard. But I have the problem, that I have to keep the mutex locked when entering asynchronous callbacks.

Take this code for example:

std::map<std::size_t, std::set<std::size_t>> my_map;

size_t bar1 = ...;
size_t bar2 = ...;

std::lock_guard guard(my_map); // lock the map
my_map[p].insert(10);
foo(bar1, [&my_map](const auto& p){
    my_map[p].insert(10);

    // here we can unlock
});

foo is computing sth and then asynchronously calling the given lambda function and passing a parameter e to it. I need my_map to be locked the whole time. Keep in mind, that this is just an code example which might not map the real problem, so please don't optimize my given code.