c++ - Typedef in template class not working

That might be a silly question, but I'm staring at this code for a while and can't think of what's wrong. On compiling:

#include 
#include 

I get:

foo.cpp:8: error: template declaration of ‘bool add_to_string_map’
foo.cpp:8: error: expected ‘)’ before ‘map’
foo.cpp:8: error: expected primary-expression before ‘str’
foo.cpp:8: error: expected primary-expression before ‘x’

(Definition of my_string_map class was taken from another thread of this forum)

When i specialize what template type I'm using, like in

bool add_to_string_int_map(my_string_map::type map,
        std::string str, int x) {
    if (map.find(str) != map.end()) 
        return false;

    map[str] = x;
    return true;
}

everything works fine. Why it's not working and/or how to get it working?

Thanks in advance for your help