Implementation of the song 99 bottles of beer in cpp

99Bottles.cpp

//
// Created by Ajay Guru on 10/17/17.
//


#include <iostream>

using namespace std;

template<bool small, int I>
struct pretty_printer;

#define SMALL_PRETTY_PRINTER(num, string) \
template<>\
struct pretty_printer<true, num>\
{\
    static void print()\
    {\
        cout << string;\
    }\
};

SMALL_PRETTY_PRINTER(0, "No")
SMALL_PRETTY_PRINTER(1, "One")
SMALL_PRETTY_PRINTER(2, "Two")
SMALL_PRETTY_PRINTER(3, "Three")
SMALL_PRETTY_PRINTER(4, "Four")
SMALL_PRETTY_PRINTER(5, "Five")
SMALL_PRETTY_PRINTER(6, "Six")
SMALL_PRETTY_PRINTER(7, "Seven")
SMALL_PRETTY_PRINTER(8, "Eight")
SMALL_PRETTY_PRINTER(9, "Nine")
SMALL_PRETTY_PRINTER(10, "Ten")
SMALL_PRETTY_PRINTER(11, "Eleven")
SMALL_PRETTY_PRINTER(12, "Twelve")
SMALL_PRETTY_PRINTER(13, "Thirteen")
SMALL_PRETTY_PRINTER(14, "Fourteen")
SMALL_PRETTY_PRINTER(15, "Fifteen")
SMALL_PRETTY_PRINTER(16, "Sixteen")
SMALL_PRETTY_PRINTER(17, "Seventeen")
SMALL_PRETTY_PRINTER(18, "Eighteen")
SMALL_PRETTY_PRINTER(19, "Nineteen")

#undef SMALL_PRETTY_PRINTER

template<int ones>
inline void
print_ones();

#define ONES_PRINTER(ones, string) \
template<> \
inline void \
print_ones<ones>() \
{\
  cout << string;\
}

ONES_PRINTER(0, " ")
ONES_PRINTER(1, " one")
ONES_PRINTER(2, " two")
ONES_PRINTER(3, " three")
ONES_PRINTER(4, " four")
ONES_PRINTER(5, " five")
ONES_PRINTER(6, " six")
ONES_PRINTER(7, " seven")
ONES_PRINTER(8, " eight")
ONES_PRINTER(9, " nine")

#undef ONES_PRINTER

template<int tens>
inline void
print_tens();

#define TENS_PRINTER(tens, string) \
template<> \
inline void \
print_tens<tens>() \
{\
  cout << string;\
}

TENS_PRINTER(2, "Twenty")
TENS_PRINTER(3, "Thirty")
TENS_PRINTER(4, "Forty")
TENS_PRINTER(5, "Fifty")
TENS_PRINTER(6, "Sixty")
TENS_PRINTER(7, "Seventy")
TENS_PRINTER(8, "Eighty")
TENS_PRINTER(9, "Ninety")

#undef TENS_PRINTER

template<int I>
struct pretty_printer<false, I>
{
    static void print(){
        print_tens<(I - I%10)/10>();
        print_ones<(I%10)>();
    }
};

template<int I>
void pretty_print()
{
    pretty_printer<(I<20), I>::print();
}

template<int I>
inline void
BottlesOfBeer()
{
    pretty_print<I>();
    cout << " bottles of beer" ;
}

template<>
inline void
BottlesOfBeer<1>()
{
    pretty_print<1>();
    cout << " bottle of beer" ;
}

template<int I>
inline void
BottlesOfBeerOnTheWall()
{
    BottlesOfBeer<I>();
    cout << " on the wall";
}

template<int I>
inline void stanza()
{
    BottlesOfBeerOnTheWall<I>();
    cout << ",\n";
    BottlesOfBeer<I>();
    cout <<",\n";
}

template<int I>
inline void bridge()
{
    cout   << "Take one down, pass it around," << endl;
    BottlesOfBeerOnTheWall<I-1>();
    cout <<",\n";
}

template<>
inline void bridge<0>()
{
    cout << "Go to the store and buy some more," << endl;
    BottlesOfBeerOnTheWall<99>();
}

template<int I>
inline void verse()
{
    stanza<I>();
    bridge<I>();
}

template<int I>
inline void sing ()
{
    verse<I>();
    cout << endl;
    sing<I-1>();
}


template<>
inline void sing<0> ()
{
    verse<0>();
}

int main () {
    sing<99>();
}