Can non-class functions be made private?

Question

I have some functions in a namespace I made that are used throughout my program.

In header file:

namespace NQueens
{
    static int heur = 0;
    int CalcHeuristic(char** state, int size);
    void CalcHorzH(char ** state, int &heuristic, int size);
    void CalcColH(char ** state, int &heuristic, int size);
    void CalcDiagH(char ** state, int &heuristic, int size);
    int calcCollisions(int queensPerRow, int size);
}

Everything works fine. However the only function that actually gets called from my outside program code is the CalcHeuristic(char** state, int size) function. This function then calls the other functions itself.

Since these do not belong to a class my compiler will not let me declare the other functions as private. Is there a way to do this? Should I even worry about it?

Answer 1

Don't declare them in the header, put them in an anonymous namespace in the implementation file.

Example header:

namespace NQueens
{
    int CalcHeuristic(char** state, int size);
}

Example implementation:

namespace
{
    static int heur = 0;
    void CalcHorzH(char ** state, int &heuristic, int size);
    void CalcColH(char ** state, int &heuristic, int size);
    void CalcDiagH(char ** state, int &heuristic, int size);
    int calcCollisions(int queensPerRow, int size);
}

namespace NQueens
{
    int CalcHeuristic(char** state, int size)
    {
        // ...
    }
}

namespace
{
    void CalcHorzH(char ** state, int &heuristic, int size) {}
    void CalcColH(char ** state, int &heuristic, int size) {}
    void CalcDiagH(char ** state, int &heuristic, int size) {}
    int calcCollisions(int queensPerRow, int size) { return 0; }
}