Question

If I want the unordered map find function to return a bool value, how would I go about doing that?

Here’s my code right now.

bool NS_SymbolTable::SymbolTable::Contains(std::string lexeme)
    {
        SymbolTable *tempSymbolTable = this;
        std::unordered_map<std::string, Identifier*>::iterator it = tempSymbolTable->hashtable.find(lexeme);

        return std::boolalpha;
    }

What else do I neeed to do ? Is it possible to return a bool? There is little to no documentation on this that I have found.

This is where I got an example from http://msdn.microsoft.com/en-us/library/bb982431.aspx

Answer 1

For documentation look std::unordered_map::find. There it says:

Return value
iterator to an elements with key key. If no such element is found, past-the-end (see end()) iterator is returned.

To get boolean value indicating whether an element is present, use

bool contained = it != tempSymbolTable->hashtable.end();