[SOLVED] Is there atomic increment with the check preconditions, that the atomic value was less than the specified value?

Is there atomic increment with the check preconditions, that the atomic value was less than the specified value?

Is in the new standard C++ atomic increment operation with the check preconditions before the incremented the value, that the atomic value was less than the specified value?

Can I do it easier and faster than the following code?

int atomic_inc(std::atomic_int& val, int less_than) {
 int new_val;
 int old_val = val.load();
 do
 {
   if (old_val > less_than) return old_val;
   new_val = old_val + 1;
 } while (!val.compare_exchange_weak(old_val, new_val));

 return new_val;
}

If somebody don't know how works compare_exchange_weak: compare_exchange_weak reads val, compares with old_val, and if they are not equal then saves val to old_val. If it is equal then save new_val to val.

Solution

No, there is no special support for incrementing values less than a value. Your code is as efficient as you can get. There is no wait-free variant in C++11

There is an unlimited number of possible "increment if X" patterns. The hardware manufacturers decided that "increment if not changed" is the only thing they need to support.

In theory you could invent a hardware platform with a special assembly code for it, but C++11 does not directly target that.