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 Code: string auto array

Header

//##############################################################################
// class for an array of strings that automatically expands as needed.
//##############################################################################
class string_auto_array{
private:
    int     _next;
    int     _size;
    int     _chunk;
    char  **_array;
    int     resize(int index);
public:
    string_auto_array(int chunk = 10, int size = 10);
    ~string_auto_array();
    int     set(int index, char *value);
    char   *get(int index);
    int     get(int index, char **value);
    char  *&operator[] (unsigned i) { return _array[i]; }
    int     size() { return _size; }
    int     next() { return _next; }
};

Code

//##############################################################################
string_auto_array::string_auto_array(int chunk, int size)
{
    _chunk      = chunk;
    _size       = (size / _chunk + 1) * _chunk;
    _next       = 0;
    _array      = new char *[_size];
    for (int i = 0; i < _size; i++) {
        _array[i] = NULL;
    }
//    if (_array == NULL) {
//        printf("array creation failed\n");
//    }
}

//##############################################################################
string_auto_array::~string_auto_array()
{
    int i;
    printf("auto array destroyed\n");
    delete[] _array;
}

//##############################################################################
int string_auto_array::resize(int index)
{
    int new_size = (index / _chunk + 1) * _chunk;
    // here is where we need to expand the array
//    printf("resize from %d to %d\n", _size, new_size);
    char **n, **o;
    n = new char *[new_size];
    if (n != NULL) {
        // creation of new array succeeded
        // copy old stuff over
        int i;
        for (i = 0; i < _next; i++) {
            n[i]  = _array[i];
        }
        for (; i < new_size; i++) {
            n[i] = NULL;
        }
        // destroy old array
        o     = _array;
        _array = n;
        delete[] o;
        _size = new_size;
    }        
    else {
        fprintf(stderr, "expansion of array failed\n");
        exit(1);
    }
}

//##############################################################################
int string_auto_array::set(int index, char *value)
{
//    printf("insert %dth element..", index);
    if (index >= _size) {
        resize(index);
    }
    if (index >= _next) {
//        printf("bump _next to %d, was %d\n", index + 1, _next);
        _next = index + 1;
    }
    _array[index] = value;
//    printf("_next = %d\n", _next);
}

//##############################################################################
char *string_auto_array::get(int index)
{
    if (index < _next) {
        return _array[index];
    }
}

//##############################################################################
int string_auto_array::get(int index, char **value)
{
    if (index < _next) {
        *value = _array[index];
        return 1;
    }
    else {
        return 0;
    }
}

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