Recursive function to loop and stack

Feasibility (100%):

From here, we know that any recursive function can be converted to iterate (into a loop) but you need to use a stack yourself to keep the state.

How to do this (generally):

You can check out the article How to replace recursive functions using stack and while-loop to avoid the stack-overflow, which gives examples and steps (10 steps/rules) on how to convert recursive functions to stack and while-loop. See the following part for real example.

Example:

Take the following recursive function as an example:

// Recursive Function "First rule" example
int SomeFunc(int n, int &retIdx)
{
    ...
        if(n>0)
        {
            int test = SomeFunc(n-1, retIdx);
            test--;
            ...
                return test;
        }
        ...
            return 0;
} 

After applying the 10 rules/steps introduced in the article (details shown in comments), you will get:

// Conversion to Iterative Function
int SomeFuncLoop(int n, int &retIdx)
{
    // (First rule)
    struct SnapShotStruct {
        int n;        // - parameter input
        int test;     // - local variable that will be used 
        //     after returning from the function call
        // - retIdx can be ignored since it is a reference.
        int stage;    // - Since there is process needed to be done 
        //     after recursive call. (Sixth rule)
    };
    // (Second rule)
    int retVal = 0;  // initialize with default returning value
    // (Third rule)
    stack<SnapShotStruct> snapshotStack;
    // (Fourth rule)
    SnapShotStruct currentSnapshot;
    currentSnapshot.n= n;          // set the value as parameter value
    currentSnapshot.test=0;        // set the value as default value
    currentSnapshot.stage=0;       // set the value as initial stage
    snapshotStack.push(currentSnapshot);
    // (Fifth rule)
    while(!snapshotStack.empty())
    {
        currentSnapshot=snapshotStack.top();
        snapshotStack.pop();
        // (Sixth rule)
        switch( currentSnapshot.stage)
        {
        case 0:
            // (Seventh rule)
            if( currentSnapshot.n>0 )
            {
                // (Tenth rule)
                currentSnapshot.stage = 1;            // - current snapshot need to process after
                //     returning from the recursive call
                snapshotStack.push(currentSnapshot);  // - this MUST pushed into stack before 
                //     new snapshot!
                // Create a new snapshot for calling itself
                SnapShotStruct newSnapshot;
                newSnapshot.n= currentSnapshot.n-1;   // - give parameter as parameter given
                //     when calling itself
                //     ( SomeFunc(n-1, retIdx) )
                newSnapshot.test=0;                   // - set the value as initial value
                newSnapshot.stage=0;                  // - since it will start from the 
                //     beginning of the function, 
                //     give the initial stage
                snapshotStack.push(newSnapshot);
                continue;
            }
            ...
                // (Eighth rule)
                retVal = 0 ;

            // (Ninth rule)
            continue;
            break; 
        case 1: 
            // (Seventh rule)
            currentSnapshot.test = retVal;
            currentSnapshot.test--;
            ...
                // (Eighth rule)
                retVal = currentSnapshot.test;
            // (Ninth rule)
            continue;
            break;
        }
    }
    // (Second rule)
    return retVal;
} 

BTW, the above article is the Prize winner in Competition <Best C++ article of July 2012> of CodeProject, so it should be trust-able. :)