How to delete an object from a map which contains a vector as value in C++ -

i have map contains of vector of type messages.

std::map<std::string, std::vector<message>> storage; 

class message has 3 member variables.

class message { private:     std::string msg;     std::string msg_type;     int priority; } 

now trying delete object has priority(say 3) map. using following function it. doesn't work.

void deletebymessagepriority(int priority) {     if (checkpriorityofmessage(priority))     {          (std::map<std::string, std::vector<message>>::iterator = storage.begin(); != storage.end(); it++)         {             std::vector<message> listofmsgs = it->second;             (std::vector<message>::iterator vec_it = listofmsgs.begin(); vec_it != listofmsgs.end(); vec_it++)              //for(int index = 0;index < listofmsgs.size();index++)             {                 if (vec_it->getpriority() == priority)                 {                     listofmsgs.pop_back();                 }             }           }     } } 

look @ this:

            if (vec_it->getpriority() == priority)             {                 listofmsgs.pop_back();             } 

you're looking @ priority of 1 message (the 1 referred vec_it), deleting if matches?

instead of writing own loop, i'd use erase , std::remove_if remove items care in vector @ once.

for (auto & item : storage) {     auto &vec = item.second;     auto start_junk = std::remove_if(         vec.begin(), vec.end(),          [=](message const &m) { return m.priority == priority; });     vec.erase(start_junk, vec.end()); }