#include <stdio.h>
#include <stdarg.h>
#include <string.h>

// ----------------------------------------------------------------------------------------------------------------------------

class CString
{
protected:
    char *String;

public:
    CString();
    CString(const char *DefaultString);
    CString(const CString &DefaultString);

    ~CString();

    operator char* ();

    CString& operator = (const char *NewString);
    CString& operator = (const CString &NewString);
    CString& operator += (const char *NewString);
    CString& operator += (const CString &NewString);

    friend CString operator + (const CString &String1, const char *String2);
    friend CString operator + (const char *String1, const CString &String2);
    friend CString operator + (const CString &String1, const CString &String2);

    void Append(const char *Format, ...);
    void Set(const char *Format, ...);
    void Empty();
};

#include "string.h"

// ----------------------------------------------------------------------------------------------------------------------------

CString::CString()
{
    String = NULL;
    Empty();
}

CString::CString(const char *DefaultString)
{
    String = NULL;
    Empty();
    Set(DefaultString);
}

CString::CString(const CString &DefaultString)
{
    String = NULL;
    Empty();
    Set(DefaultString.String);
}

CString::~CString()
{
    delete [] String;
}

CString::operator char* ()
{
    return String;
}

CString& CString::operator = (const char *NewString)
{
    if(String != NewString) Set(NewString);
    return *this;
}

CString& CString::operator = (const CString &NewString)
{
    if(this != &NewString) Set(NewString.String);
    return *this;
}

CString& CString::operator += (const char *NewString)
{
    Append(NewString);
    return *this;
}

CString& CString::operator += (const CString &NewString)
{
    Append(NewString.String);
    return *this;
}

CString operator + (const CString &String1, const char *String2)
{
    CString String = String1;
    String += String2;
    return String;
}

CString operator + (const char *String1, const CString &String2)
{
    CString String = String1;
    String += String2;
    return String;
}

CString operator + (const CString &String1, const CString &String2)
{
    CString String = String1;
    String += String2;
    return String;
}

void CString::Append(const char *Format, ...)
{
    va_list ArgList;

    va_start(ArgList, Format);

    int AppendixLength = _vscprintf(Format, ArgList);
    char *Appendix = new char[AppendixLength + 1];
    vsprintf_s(Appendix, AppendixLength + 1, Format, ArgList);

    char *OldString = String;
    int OldStringLength = (int)strlen(String);

    int StringLength = OldStringLength + AppendixLength;
    String = new char[StringLength + 1];
    
    strcpy_s(String, StringLength + 1, OldString);
    strcat_s(String, StringLength + 1, Appendix);

    delete [] OldString;
    delete [] Appendix;
}

void CString::Set(const char *Format, ...)
{
    va_list ArgList;

    va_start(ArgList, Format);

    delete [] String;

    int StringLength = _vscprintf(Format, ArgList);
    String = new char[StringLength + 1];
    vsprintf_s(String, StringLength + 1, Format, ArgList);
}

void CString::Empty()
{
    delete [] String;
    String = new char[1];
    String[0] = 0;
}