Embedded Linux C + + language (ix)--templates

Embedded linux C + + language (ix)--Templates

generic type (Generic programming) Meaning that can be manipulated on a variety of data types. representative works of generic programming STL is an efficient, generic, interoperable software component.
generic programming was first born in In C + + , the goal is to implement STL (Standard Template Library) for C + +. The language support mechanism is the template (Templates). The spirit of the template is actually very simple: parameterized type. In other words, the type information in an algorithm or class that is originally specific to a type is pumped out and made into a template parameter T.

First, function Templates1. generics implemented by function overloading

 #include  <iostream>using namespace std;void  Swap (INT&NBSP;&A,&NBSP;INT&&NBSP;B) {    int t = a;     a = b;    b = t;} Void swap (double &a,double b) {    double t = a;     a = b;    b = t;} Int main () {    int ia = 10; int ib = 20;     swap (IA,IB);    cout<<ia<<ib<<endl;     double da = 10, db = 20;    swap (DA,DB);     cout<<da<<db<<endl;    return 0;} 

2. function Templates

Syntax format

Template<typename/class type parameter table >
return type function template Name ( function parameter list )
{
function template definition Body
}

3.

 #include  <iostream>using namespace std;template  <typename t>void swap (t& a,t &b ) {    T  T = a;    a = b;    b = t;} Int main () {    int ia = 10; int ib = 20;     swap (Ia,ib); //swap<int> (IA,IB);     cout<<ia<<ib <<endl;    double da = 10, db = 20;     swap (da,db); //swap<double> (da,db);    cout<<da<<db<< endl;    string sa = "China"; string sb =  "America";     swap (SA,SB);    cout<<sa<<sb<<endl;     return 0;} 

A function template that applies only to functions with the same number of arguments and different types, and with the same function body. If the number is different, you cannot use a function template.

second, class template 1. Definition of class template

Definition of a class template

Template<typename t>
Class Stack
{ }

Define member functions within a class

Template<typename t>
Class Stack
{
Public
Stack (int size)
{
Space = new T[size];
top = 0;
}
}

Out-of-class definition functions

Template<typename t>
void Stack<t>::p ush (T data)
{
space[top++] = data;
}

Class template is instantiated as a template class

stack<double> s (100);

A class template is an abstraction of a class that is an instance of a class template.

2. class Template Instance

#include  <iostream> #include  <stdlib.h> #include  <stdio.h> #include  < string.h>using namespace std;template<typename t>class stack{public:     stack (int size)     {        space  = new T[size];        top = 0;     }    ~stack ();     bool isempty ();     bool isfull ();     void push (T data);    t  Pop ();p rivate:    t* space;    int top;}; Template<typename t>stack<t>::~stack () {    delete []space;} Template<typename t>bool stack<t>::isempty () {    return top  == 0;} Template<typename t>bool stack<t>::isfull () {    return top == 1024;} Template<typename t>void stack<t&gt::p ush (t data) {    space[top++ ] = data;} Template<typename t>t stack<t>::p op () {    return space[--top];} Int main () {    stack<double> s (+);  //stack<string> s (100 );     if (!s.isfull ())         s.push (10.3);     if (!s.isfull ())         s.push (;   )  if (!s.isfull ())         s.push ();     if (! S.isfull ())         s.push (+),     if (!s.isFull ())         s.push (    while) (!s.isEmpty ())           cout<<s.pop () <<endl;    return 0;} 

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Embedded Linux C + + language (ix)--templates