map inserting key values into wrong key?

Question

I have been having this problem for awhile with my code, looking for my mistake I can't see it. I have a map, map I am mapping keywords to the values.
My problem is sometimes when inserting keyword = "Blue" the value is inserting into the Key for "Red".
So instead of,
Key: Red, Value: obj1, obj2
Key: Blue, Value: obj3, obj4
I get,
Key: Red, Value: obj1, obj2, obj4 (obj4 should be keyed to Blue)
Key: Blue, Value: obj3

Not sure what it can be since the same version of the code works for other maps that I have, they just don't have as many Keys.

addKeywordsForObject(const Object* const object, int nKeywords, ...)
{
va_list     keywords;
char        *keyword;

va_start(keywords, nKeywords);
for (int i = 0; i < nKeywords; i++) {
    keyword = va_arg(keywords, char*);

    if(objectToKeywordMap.find(keyword) == objectToKeywordMap.end()) {  
        keywordObject = new ObjectSet();
        keywordObject->insert(const_cast<Object* const>(object));
        objectToKeywordMap.emplace(StringToObjectSetMap::value_type(keyword,keywordObject));
    }
    else {
        keywordObject->insert(const_cast<Object* const>(object));   
        objectToKeywordMap.emplace(StringToObjectSetMap::value_type(keyword,keywordObject));
    }
}
va_end(keywords);
}  

Answer 1

most probably the problem is that you haven't define your sort function for the key type that that your map has. You need to 'tell' the map how to sort the index-type

For example:

struct sortKey{
bool operator()(key_type const& k1, key_type const& k2){
//define your sort criteria here
}

}
std::map<key_type,value_type,sortKey> the_map;

Please comment if you think there is something else that you are missing.

Answer 2

I see no declaration for keywordObject , so I shall assume it's a global. The case of adding a new object to a keyword which is already present is dealt with in the else . What is the value of keywordObject in this case? Who sets it?

There are a number of other problems with this code, some mentioned in other answers and comments.

• missing return type for addKeywordsForObject
• possible usage of char* as a map key which requires special handling (not clear, because you haven't shown the declaration of StringToObjectSetMap )
• a function which takes a variable number of parameters by using ellipsis (almost never a good idea in C++)
• use of a global variable where a local variable is appropriate