Example 13-7

Example 13-7 A Function Template in a header file

Ex13-7h

#ifndef EX13_7_H
#define EX13_7_H

#include <iostream>

template <typename U> void swap(U& a,U& b)
{
    U temp;
    temp = a;
    a = b;
    b = temp;
}

template <typename T> void sort(T* a,int size)
{
    int i,j;
    for (i = 1; i < size; i++)
        for (j = 0; j < i; j++)
            if ( a[i] < a[j] ) swap(a[i],a[j]);
}

template <typename V> void arrayPrint(const V* a,int size)
{
    int i;
    for (i = 0; i < size; i++) std::cout << a[i] << std::endl;
    std::cout << std::endl;
}

#endif

Ex13-7.cpp

#include "ex13-7.h"
#include <iostream>
using namespace std;

class Fraction
{
private:
    int numer,denom;
public:
    Fraction(int n = 0, int d = 1) : numer(n), denom(d) {}
    void assign(int n, int d)
    {
        numer = n;
        denom = d;
    }
    int operator<(Fraction& f);
    friend ostream& operator<<(ostream& s, const Fraction& f);
};

int Fraction::operator<(Fraction& f)
{
    return (static_cast<float>(numer)/denom <
            static_cast<float>(f.numer)/f.denom);
}

ostream& operator<<(ostream& s,const Fraction& f)
{
    s << f.numer << '/' << f.denom;
    return s;
}

class Card
{
protected:
    int pips;
    int suit;
public:
    Card(int n = 0) : pips(n % 13), suit(n / 13)
    { }

    bool operator<(const Card& c) const
    {
        return pips < c.pips;
    }
    static const string PipsName[13];
    static const string SuitName[4];
    friend ostream& operator<<(ostream&, const Card&);
};

const string Card::PipsName[13] = {"two","three","four","five",
"six","seven","eight","nine","ten","jack","queen","king","ace"};
const string Card::SuitName[4] = {"clubs","diamonds","hearts","spades"};

ostream& operator<<(ostream& out, const Card& card)
{
    out << Card::PipsName[card.pips] << " of " <<
        Card::SuitName[card.suit];
    return out;
}

class PinocleCard : public Card
{
public:
    PinocleCard(int n = 0) : Card(n)
    {
        pips = n % 6 + 7;
        suit = n / 2 % 4;
    }
    int operator<(PinocleCard&);
};

int PinocleCard::operator<(PinocleCard& c)
{
    if (pips != 8 && c.pips != 8)
        return (pips < c.pips);
    else if (pips == 8 && c.pips != 12)
        return 0;
    else if (c.pips == 8 && pips != 12)
        return 1;
    else
        return 0;
}

int main()
{
    // array of int
    int a1[5] = { 3, 5, 1, 9, 94};
    arrayPrint(a1,5);
    sort(a1,5);
    arrayPrint(a1,5);

    // array of double
    double a2[4] = { 3.7, 1.5, -1.1,.9};
    arrayPrint(a2,4);
    sort(a2,4);
    arrayPrint(a2,4);

    // array of char
    char a3[4] = {"hey"};
    arrayPrint(a3,3);
    sort(a3,3);
    arrayPrint(a3,3);

    // array of Fractions
    Fraction a4[4] {{2,3},{1,2},{3,4},{5,9}};
    arrayPrint(a4,4);
    sort(a4,4);
    arrayPrint(a4,4);

    // array of cards
    Card a5[4] = {47,23,43,1};

    arrayPrint(a5,4);
    sort(a5,4);
    arrayPrint(a5,4);

    // array of PinocleCards
    PinocleCard a6[6] = {32,18,41,10,13,27};
    arrayPrint(a6,6);
    sort(a6,6);
    arrayPrint(a6,6);
}