Testing the use of conceptional constance.

const.cpp

#include <iostream>
#include "MoneyChanger.h"

//Testing conceptional constance with 'mutable' keyword
class testClass {
    /* make it mutable then callable by const fucntion.
     * It's better to make memberfunction called by this class
     * be const function. In that way you do not need mutable
     * funciton here. But some time you cannot modify it,
     * for example you are using prebuild library  */
    mutable MoneyChanger mc;
public:
    // you must use a user define constructor, when you construct a const object.
    testClass() {}
    const long long test(double dollars) const{
        return mc.howManyCombinations(dollars);
    }
};

int main(int argc, const char * argv[])
{
    // this is conceptional constance instead of bit-wise constance.
    const testClass normalTestObj;
    std::cout << normalTestObj.test(100) << "\n";
    // next line will be very fast, because last line do all computation
    // needed and save results into mutable member.
    std::cout << normalTestObj.test(10) << "\n";
    return 0;
}