Function overloading — two functions only differ by a default parameter

Question

class A{
    public:
        void foo(int x)
        {
            cout << \"foo with one\\n\";
        }

        void foo(int x, int y=10)
        {
                 


        

Answer 1

The ambiguity doesn't happen because of optional parameters but only happens when you have the same kind of prototype with same optionals but different names.. thats what I figured out..

I actually thought i got lucky when my example similar to yours worked.. but when I put 2 different prototype names with same optional parameters then it started complaining about ambiguities

This below gives the ambiguity error

void UpdateTextColor(HWND hwndControl, DWORD text_color, DWORD back_color, BOOL control_back_color);
void CreateColoredText(HWND hwndControl, DWORD text_color, DWORD back_color, BOOL control_back_color);

void UpdateTextColor(HWND hwndControl, DWORD text_color, DWORD back_color, BOOL control_back_color = FALSE)
{
   //...
}

void CreateColoredText(HWND hwndControl, DWORD text_color, DWORD back_color, BOOL control_back_color = FALSE)
{
   //...
}

But this doesn't and note I am still using a optional parameter

void UpdateTextColor(HWND hwndControl, DWORD text_color, DWORD back_color);
void CreateColoredText(HWND hwndControl, DWORD text_color, DWORD back_color, BOOL control_back_color);

void UpdateTextColor(HWND hwndControl, DWORD text_color, DWORD back_color)
{
   //...
}

void CreateColoredText(HWND hwndControl, DWORD text_color, DWORD back_color, BOOL control_back_color = FALSE)
{
   //...
}

//My call is like this (note only 3 params used out of 4)

CreateColoredText(GetDlgItem(hDlg, BLAHBLAH), RGB(0, 0, 0), RGB(127, 127, 127));