Overflow is well-defined for unsigned integers; they will wrap to zero.
So we could just do
if (access_counter==0) last_access.fill(0);
before return cache[i];.
Overflow is well-defined for unsigned integers; they will wrap to zero.
So we could just do
```
if (access_counter==0)
last_access.fill(0);
```
before `return cache[i];`.