understanding std::findif() using a lamda on std::pair

It is my understanding that std::find_if() below returns an iterator to the first element in the range of arg for which the third argument (lamda function) returns true. Is that correct?

Could somebody explain why there isn't an iterator defined like this std::pair<std::string, std::type_index>::iterator = std::find_if(...)?

Where is the iterator returned by std::findif() stored and how can you call ->second on its own and not on an iterator?

and why is there a != args_.end() after the closing brace of std::find_if?

std::type_index argType(const std::string& name) const
{
    return std::find_if(args_.begin(), args_.end(),
        [&name](std::pair<std::string, std::type_index> arg)->bool
        {
            return arg.first == name;
        }
    )->second;
}