Safe and effective way to put a mutex on a container entry
The mutex does not require to be moved:
Imagine that every row in your map is like:
template <class T>class row{ shared_ptr<mutex> m; T data; ...};So if your row need to be moved or copied, there is no problem.
Then, you may access the mutex from every process to access the data.
Of course, you need a global mutex to perform changes on the whole map: insert / delete / [] / any other operation that change the state of the map.
EDITED:
Following a simple example of code with a mutex in every row. (It does not implement anything else that just the data structure)
#include <memory>#include <map>#include <mutex>template <class T>class row{ std::shared_ptr<std::mutex> m; T data;public: row( std::shared_ptr<std::mutex> mut): m(mut){};};auto main () -> int{ std::shared_ptr<std::mutex> mut(new std::mutex); std::map<int,row<int>> db; row<int> a(mut); db.insert(std::pair<int, row<int>>(1, a)); return 0;}