I have 2 elements (for now) map:

#define IDI_OBJECT_5001 5001
#define IDI_OBJECT_5002 5002
    /.../


ResourcesMap[IDI_OBJECT_5001] = "path_to_png_file1";
ResourcesMap[IDI_OBJECT_5002] = "path_to_png_file2";

I'm trying to implement method for searching this map. I'm passing string argument (file path) and method return int (key value of map)

int ResFiles::findResForBrew(string filePath)
{
string value = filePath;
int key = -1;
for (it = ResourcesMap.begin(); it != ResourcesMap.end(); ++it)
{
    if (/*checking if it->second == value */)
    {
        key = it->first;
        break;
    }
}
return key;
}

How I could check when it->second-> == value, and then return that key? I would be grateful for some help. Thanks in advance.