C++ “error: passing 'const std::map >' as 'this' argument of …”

Question

With the following code (excerpted for brevity):

color.h:

class color {
public:
    color();

    enum colorType {
        black, blue, green, cyan,          


        

Answer 1

string color::getColorText() const {
    return colors[cColortype];
}

The issue is that you've marked the function as const. The operator[] on std::map is marked as non-const, and cannot be used in a const function like this. You need to manually use std::map::find (or other mechanism) to search for the input type and handle the case where it's not found.

If you're using C++11, you can instead use std::map::at, which IS allowed to be used on a constant map, and throws an exception if the requested element is not present.