map::count

[pretty87]

If the map is like

std::map<int, std::string> myMap
myMap[1]="ab"
myMap[2]="bb"
myMap[3]="ba"

I have to check if a string is present in the map or not
myMap.count() wont work..Can anyone tell me how can I for example check if "bb" exist in the map or not
Thanks

[helios]

http://www.cplusplus.com/reference/stl/map/find/

[ne555]

find and count operates on the key, not the value.
You can try this

for(it=m.begin(); it!=m.end(); it++)
    if(it->second == value)
        return true;
return false;

[pretty87]

Is there any other way as I have to use it a couple of times and its making my program really slow

[jsmith]

Option 1. Change it to std::map< std::string, int >.

Option 2. Use boost::multi_index_container<>.

[Galik]

You could keep a parallel std::set<> with all your values in.

[moorecm]

I've recently become an advocate of boost::multi_index_container. It would be perfect for this.

Anyway, here are some practical thoughts about your problem:

1. First of all, unless you really need the integer key, consider just using a std::set<std::string>.

2. You could create a small predicate functor and pass it to std::find_if. Note that this would be O(n) lookup.