A C++ sablon a C++-hoz hozzáadott hatékony szolgáltatás. Lehetővé teszi az általános osztályok és általános függvények meghatározását, és így támogatást nyújt az általános programozáshoz. Az általános programozás egy olyan technika, ahol az általános típusokat paraméterekként használják az algoritmusokban, hogy azok különféle adattípusokhoz működjenek.

A sablonok kétféleképpen ábrázolhatók:

• Funkciósablonok
• Osztálysablonok

Funkciósablonok:

Megadhatunk sablont egy függvényhez. Például, ha van egy add() függvényünk, akkor az add függvény verzióit létrehozhatjuk az int, float vagy double típusú értékek hozzáadásához.

Osztály sablon:

Megadhatunk egy sablont egy osztályhoz. Például létrehozható egy osztálysablon a tömbosztályhoz, amely különféle típusú tömböt fogadhat el, például int tömböt, float tömböt vagy dupla tömböt.

Funkciósablon

• Az általános függvények a függvénysablon fogalmát használják. Az általános függvények olyan műveletek halmazát határozzák meg, amelyek a különféle típusú adatokra alkalmazhatók.
• Az adatok típusa, amelyekkel a függvény működni fog, a paraméterként átadott adatok típusától függ.
• Például a Gyors rendezési algoritmust egy általános függvény segítségével valósítják meg, megvalósítható egész számok tömbjére vagy lebegőpontok tömbjére.
• Az általános függvény a kulcsszósablon használatával jön létre. A sablon határozza meg, hogy milyen függvény fog működni.

A függvénysablon szintaxisa

 template ret_type func_name(parameter_list) { // body of function. } 

Ahol Ttype : Ez a függvény által használt adattípus helyőrző neve. A függvénydefiníción belül használatos. Ez csak egy helyőrző, hogy a fordító automatikusan lecseréli ezt a helyőrzőt a tényleges adattípusra.

médiaátvitel

osztály : Az osztály kulcsszó egy általános típus megadására szolgál a sablondeklarációban.

Nézzünk egy egyszerű példát egy függvénysablonra:

 #include using namespace std; template T add(T &amp;a,T &amp;b) { T result = a+b; return result; } int main() { int i =2; int j =3; float m = 2.3; float n = 1.2; cout&lt;<'addition of i and j is :'< <add(i,j); cout<<'
'; cout<<'addition m n <add(m,n); return 0; } < pre> <p> <strong>Output:</strong> </p> <pre> Addition of i and j is :5 Addition of m and n is :3.5 </pre> <p>In the above example, we create the function template which can perform the addition operation on any type either it can be integer, float or double.</p> <h3>Function Templates with Multiple Parameters</h3> <p>We can use more than one generic type in the template function by using the comma to separate the list.</p> <h2>Syntax</h2> <pre> template return_type function_name (arguments of type T1, T2....) { // body of function. } </pre> <p>In the above syntax, we have seen that the template function can accept any number of arguments of a different type.</p> <p> <strong>Let&apos;s see a simple example:</strong> </p> <pre> #include using namespace std; template void fun(X a,Y b) { std::cout &lt;&lt; &apos;Value of a is : &apos; &lt; <a<< std::endl; std::cout << 'value of b is : ' < <b<< } int main() { fun(15,12.3); return 0; pre> <p> <strong>Output:</strong> </p> <pre> Value of a is : 15 Value of b is : 12.3 </pre> <p>In the above example, we use two generic types in the template function, i.e., X and Y.</p> <h3>Overloading a Function Template</h3> <p>We can overload the generic function means that the overloaded template functions can differ in the parameter list.</p> <p> <strong>Let&apos;s understand this through a simple example:</strong> </p> <pre> #include using namespace std; template void fun(X a) { std::cout &lt;&lt; &apos;Value of a is : &apos; &lt; <a<< std::endl; } template void fun(x b ,y c) { std::cout << 'value of is : ' < <b<< c <<c<< int main() fun(10); fun(20,30.5); return 0; pre> <p> <strong>Output:</strong> </p> <pre> Value of a is : 10 Value of b is : 20 Value of c is : 30.5 </pre> <p>In the above example, template of fun() function is overloaded.</p> <h3>Restrictions of Generic Functions</h3> <p>Generic functions perform the same operation for all the versions of a function except the data type differs. Let&apos;s see a simple example of an overloaded function which cannot be replaced by the generic function as both the functions have different functionalities.</p> <p> <strong>Let&apos;s understand this through a simple example:</strong> </p> <pre> #include using namespace std; void fun(double a) { cout&lt;<'value of a is : '< <a<<'
'; } void fun(int b) { if(b%2="=0)" cout<<'number even'; else odd'; int main() fun(4.6); fun(6); return 0; < pre> <p> <strong>Output:</strong> </p> <pre> value of a is : 4.6 Number is even </pre> <p>In the above example, we overload the ordinary functions. We cannot overload the generic functions as both the functions have different functionalities. First one is displaying the value and the second one determines whether the number is even or not.</p> <hr> <h2>CLASS TEMPLATE</h2> <p> <strong>Class Template</strong> can also be defined similarly to the Function Template. When a class uses the concept of Template, then the class is known as generic class.</p> <h2>Syntax</h2> <pre> template class class_name { . . } </pre> <p> <strong>Ttype</strong> is a placeholder name which will be determined when the class is instantiated. We can define more than one generic data type using a comma-separated list. The Ttype can be used inside the class body.</p> <p>Now, we create an instance of a class</p> <pre> class_name ob; </pre> <p> <strong>where class_name</strong> : It is the name of the class.</p> <p> <strong>type</strong> : It is the type of the data that the class is operating on.</p> <p> <strong>ob</strong> : It is the name of the object.</p> <p> <strong>Let&apos;s see a simple example:</strong> </p> <pre> #include using namespace std; template class A { public: T num1 = 5; T num2 = 6; void add() { std::cout &lt;&lt; &apos;Addition of num1 and num2 : &apos; &lt;&lt; num1+num2&lt;<std::endl; } }; int main() { a d; d.add(); return 0; < pre> <p> <strong>Output:</strong> </p> <pre> Addition of num1 and num2 : 11 </pre> <p>In the above example, we create a template for class A. Inside the main() method, we create the instance of class A named as, &apos;d&apos;.</p> <h3>CLASS TEMPLATE WITH MULTIPLE PARAMETERS</h3> <p>We can use more than one generic data type in a class template, and each generic data type is separated by the comma.</p> <h2>Syntax</h2> <pre> template class class_name { // Body of the class. } </pre> <p> <strong>Let&apos;s see a simple example when class template contains two generic data types.</strong> </p> <pre> #include using namespace std; template class A { T1 a; T2 b; public: A(T1 x,T2 y) { a = x; b = y; } void display() { std::cout &lt;&lt; &apos;Values of a and b are : &apos; &lt;&lt; a&lt;<' ,'< <b<<std::endl; } }; int main() { a d(5,6.5); d.display(); return 0; < pre> <p> <strong>Output:</strong> </p> <pre> Values of a and b are : 5,6.5 </pre> <h3>Nontype Template Arguments</h3> <p>The template can contain multiple arguments, and we can also use the non-type arguments In addition to the type T argument, we can also use other types of arguments such as strings, function names, constant expression and built-in types. <strong>Let&apos; s see the following example:</strong> </p> <pre> template class array { T arr[size]; // automatic array initialization. }; </pre> <p>In the above case, the nontype template argument is size and therefore, template supplies the size of the array as an argument.</p> <p>Arguments are specified when the objects of a class are created:</p> <pre> array t1; // array of 15 integers. array t2; // array of 10 floats. array t3; // array of 4 chars. </pre> <p>Let&apos;s see a simple example of nontype template arguments.</p> <pre> #include using namespace std; template class A { public: T arr[size]; void insert() { int i =1; for (int j=0;j<size;j++) { arr[j]="i;" i++; } void display() for(int i="0;i&lt;size;i++)" std::cout << arr[i] ' '; }; int main() a t1; t1.insert(); t1.display(); return 0; < pre> <p> <strong>Output:</strong> </p> <pre> 1 2 3 4 5 6 7 8 9 10 </pre> <p>In the above example, the class template is created which contains the nontype template argument, i.e., size. It is specified when the object of class &apos;A&apos; is created.</p> <p> <strong>Points to Remember</strong> </p> <ul> <li>C++ supports a powerful feature known as a template to implement the concept of generic programming.</li> <li>A template allows us to create a family of classes or family of functions to handle different data types.</li> <li>Template classes and functions eliminate the code duplication of different data types and thus makes the development easier and faster.</li> <li>Multiple parameters can be used in both class and function template.</li> <li>Template functions can also be overloaded.</li> <li>We can also use nontype arguments such as built-in or derived data types as template arguments.</li> </ul> <br></size;j++)></pre></'></pre></std::endl;></pre></'value></pre></a<<></pre></a<<></pre></'addition>

A fenti példában létrehozzuk azt a függvénysablont, amely bármilyen típusú összeadási műveletet végrehajthat, legyen az egész, float vagy double.

Funkciósablonok több paraméterrel

Egynél több általános típust is használhatunk a sablonfüggvényben, ha vesszővel választjuk el a listát.

Szintaxis

 template return_type function_name (arguments of type T1, T2....) { // body of function. } 

A fenti szintaxisban láttuk, hogy a template függvény tetszőleges számú, eltérő típusú argumentumot képes elfogadni.

Lássunk egy egyszerű példát:

java mag java

 #include using namespace std; template void fun(X a,Y b) { std::cout &lt;&lt; &apos;Value of a is : &apos; &lt; <a<< std::endl; std::cout << \'value of b is : \' < <b<< } int main() { fun(15,12.3); return 0; pre> <p> <strong>Output:</strong> </p> <pre> Value of a is : 15 Value of b is : 12.3 </pre> <p>In the above example, we use two generic types in the template function, i.e., X and Y.</p> <h3>Overloading a Function Template</h3> <p>We can overload the generic function means that the overloaded template functions can differ in the parameter list.</p> <p> <strong>Let&apos;s understand this through a simple example:</strong> </p> <pre> #include using namespace std; template void fun(X a) { std::cout &lt;&lt; &apos;Value of a is : &apos; &lt; <a<< std::endl; } template void fun(x b ,y c) { std::cout << \'value of is : \' < <b<< c <<c<< int main() fun(10); fun(20,30.5); return 0; pre> <p> <strong>Output:</strong> </p> <pre> Value of a is : 10 Value of b is : 20 Value of c is : 30.5 </pre> <p>In the above example, template of fun() function is overloaded.</p> <h3>Restrictions of Generic Functions</h3> <p>Generic functions perform the same operation for all the versions of a function except the data type differs. Let&apos;s see a simple example of an overloaded function which cannot be replaced by the generic function as both the functions have different functionalities.</p> <p> <strong>Let&apos;s understand this through a simple example:</strong> </p> <pre> #include using namespace std; void fun(double a) { cout&lt;<\'value of a is : \'< <a<<\'
\'; } void fun(int b) { if(b%2="=0)" cout<<\'number even\'; else odd\'; int main() fun(4.6); fun(6); return 0; < pre> <p> <strong>Output:</strong> </p> <pre> value of a is : 4.6 Number is even </pre> <p>In the above example, we overload the ordinary functions. We cannot overload the generic functions as both the functions have different functionalities. First one is displaying the value and the second one determines whether the number is even or not.</p> <hr> <h2>CLASS TEMPLATE</h2> <p> <strong>Class Template</strong> can also be defined similarly to the Function Template. When a class uses the concept of Template, then the class is known as generic class.</p> <h2>Syntax</h2> <pre> template class class_name { . . } </pre> <p> <strong>Ttype</strong> is a placeholder name which will be determined when the class is instantiated. We can define more than one generic data type using a comma-separated list. The Ttype can be used inside the class body.</p> <p>Now, we create an instance of a class</p> <pre> class_name ob; </pre> <p> <strong>where class_name</strong> : It is the name of the class.</p> <p> <strong>type</strong> : It is the type of the data that the class is operating on.</p> <p> <strong>ob</strong> : It is the name of the object.</p> <p> <strong>Let&apos;s see a simple example:</strong> </p> <pre> #include using namespace std; template class A { public: T num1 = 5; T num2 = 6; void add() { std::cout &lt;&lt; &apos;Addition of num1 and num2 : &apos; &lt;&lt; num1+num2&lt;<std::endl; } }; int main() { a d; d.add(); return 0; < pre> <p> <strong>Output:</strong> </p> <pre> Addition of num1 and num2 : 11 </pre> <p>In the above example, we create a template for class A. Inside the main() method, we create the instance of class A named as, &apos;d&apos;.</p> <h3>CLASS TEMPLATE WITH MULTIPLE PARAMETERS</h3> <p>We can use more than one generic data type in a class template, and each generic data type is separated by the comma.</p> <h2>Syntax</h2> <pre> template class class_name { // Body of the class. } </pre> <p> <strong>Let&apos;s see a simple example when class template contains two generic data types.</strong> </p> <pre> #include using namespace std; template class A { T1 a; T2 b; public: A(T1 x,T2 y) { a = x; b = y; } void display() { std::cout &lt;&lt; &apos;Values of a and b are : &apos; &lt;&lt; a&lt;<\' ,\'< <b<<std::endl; } }; int main() { a d(5,6.5); d.display(); return 0; < pre> <p> <strong>Output:</strong> </p> <pre> Values of a and b are : 5,6.5 </pre> <h3>Nontype Template Arguments</h3> <p>The template can contain multiple arguments, and we can also use the non-type arguments In addition to the type T argument, we can also use other types of arguments such as strings, function names, constant expression and built-in types. <strong>Let&apos; s see the following example:</strong> </p> <pre> template class array { T arr[size]; // automatic array initialization. }; </pre> <p>In the above case, the nontype template argument is size and therefore, template supplies the size of the array as an argument.</p> <p>Arguments are specified when the objects of a class are created:</p> <pre> array t1; // array of 15 integers. array t2; // array of 10 floats. array t3; // array of 4 chars. </pre> <p>Let&apos;s see a simple example of nontype template arguments.</p> <pre> #include using namespace std; template class A { public: T arr[size]; void insert() { int i =1; for (int j=0;j<size;j++) { arr[j]="i;" i++; } void display() for(int i="0;i&lt;size;i++)" std::cout << arr[i] \' \'; }; int main() a t1; t1.insert(); t1.display(); return 0; < pre> <p> <strong>Output:</strong> </p> <pre> 1 2 3 4 5 6 7 8 9 10 </pre> <p>In the above example, the class template is created which contains the nontype template argument, i.e., size. It is specified when the object of class &apos;A&apos; is created.</p> <p> <strong>Points to Remember</strong> </p> <ul> <li>C++ supports a powerful feature known as a template to implement the concept of generic programming.</li> <li>A template allows us to create a family of classes or family of functions to handle different data types.</li> <li>Template classes and functions eliminate the code duplication of different data types and thus makes the development easier and faster.</li> <li>Multiple parameters can be used in both class and function template.</li> <li>Template functions can also be overloaded.</li> <li>We can also use nontype arguments such as built-in or derived data types as template arguments.</li> </ul> <br></size;j++)></pre></\'></pre></std::endl;></pre></\'value></pre></a<<></pre></a<<>

A fenti példában két általános típust használunk a sablonfüggvényben, azaz az X-et és az Y-t.

Funkciósablon túlterhelése

Az általános függvényt túlterhelhetjük, ami azt jelenti, hogy a túlterhelt sablonfüggvények eltérhetnek a paraméterlistában.

Értsük meg ezt egy egyszerű példán keresztül:

 #include using namespace std; template void fun(X a) { std::cout &lt;&lt; &apos;Value of a is : &apos; &lt; <a<< std::endl; } template void fun(x b ,y c) { std::cout << \'value of is : \' < <b<< c <<c<< int main() fun(10); fun(20,30.5); return 0; pre> <p> <strong>Output:</strong> </p> <pre> Value of a is : 10 Value of b is : 20 Value of c is : 30.5 </pre> <p>In the above example, template of fun() function is overloaded.</p> <h3>Restrictions of Generic Functions</h3> <p>Generic functions perform the same operation for all the versions of a function except the data type differs. Let&apos;s see a simple example of an overloaded function which cannot be replaced by the generic function as both the functions have different functionalities.</p> <p> <strong>Let&apos;s understand this through a simple example:</strong> </p> <pre> #include using namespace std; void fun(double a) { cout&lt;<\'value of a is : \'< <a<<\'
\'; } void fun(int b) { if(b%2="=0)" cout<<\'number even\'; else odd\'; int main() fun(4.6); fun(6); return 0; < pre> <p> <strong>Output:</strong> </p> <pre> value of a is : 4.6 Number is even </pre> <p>In the above example, we overload the ordinary functions. We cannot overload the generic functions as both the functions have different functionalities. First one is displaying the value and the second one determines whether the number is even or not.</p> <hr> <h2>CLASS TEMPLATE</h2> <p> <strong>Class Template</strong> can also be defined similarly to the Function Template. When a class uses the concept of Template, then the class is known as generic class.</p> <h2>Syntax</h2> <pre> template class class_name { . . } </pre> <p> <strong>Ttype</strong> is a placeholder name which will be determined when the class is instantiated. We can define more than one generic data type using a comma-separated list. The Ttype can be used inside the class body.</p> <p>Now, we create an instance of a class</p> <pre> class_name ob; </pre> <p> <strong>where class_name</strong> : It is the name of the class.</p> <p> <strong>type</strong> : It is the type of the data that the class is operating on.</p> <p> <strong>ob</strong> : It is the name of the object.</p> <p> <strong>Let&apos;s see a simple example:</strong> </p> <pre> #include using namespace std; template class A { public: T num1 = 5; T num2 = 6; void add() { std::cout &lt;&lt; &apos;Addition of num1 and num2 : &apos; &lt;&lt; num1+num2&lt;<std::endl; } }; int main() { a d; d.add(); return 0; < pre> <p> <strong>Output:</strong> </p> <pre> Addition of num1 and num2 : 11 </pre> <p>In the above example, we create a template for class A. Inside the main() method, we create the instance of class A named as, &apos;d&apos;.</p> <h3>CLASS TEMPLATE WITH MULTIPLE PARAMETERS</h3> <p>We can use more than one generic data type in a class template, and each generic data type is separated by the comma.</p> <h2>Syntax</h2> <pre> template class class_name { // Body of the class. } </pre> <p> <strong>Let&apos;s see a simple example when class template contains two generic data types.</strong> </p> <pre> #include using namespace std; template class A { T1 a; T2 b; public: A(T1 x,T2 y) { a = x; b = y; } void display() { std::cout &lt;&lt; &apos;Values of a and b are : &apos; &lt;&lt; a&lt;<\' ,\'< <b<<std::endl; } }; int main() { a d(5,6.5); d.display(); return 0; < pre> <p> <strong>Output:</strong> </p> <pre> Values of a and b are : 5,6.5 </pre> <h3>Nontype Template Arguments</h3> <p>The template can contain multiple arguments, and we can also use the non-type arguments In addition to the type T argument, we can also use other types of arguments such as strings, function names, constant expression and built-in types. <strong>Let&apos; s see the following example:</strong> </p> <pre> template class array { T arr[size]; // automatic array initialization. }; </pre> <p>In the above case, the nontype template argument is size and therefore, template supplies the size of the array as an argument.</p> <p>Arguments are specified when the objects of a class are created:</p> <pre> array t1; // array of 15 integers. array t2; // array of 10 floats. array t3; // array of 4 chars. </pre> <p>Let&apos;s see a simple example of nontype template arguments.</p> <pre> #include using namespace std; template class A { public: T arr[size]; void insert() { int i =1; for (int j=0;j<size;j++) { arr[j]="i;" i++; } void display() for(int i="0;i&lt;size;i++)" std::cout << arr[i] \' \'; }; int main() a t1; t1.insert(); t1.display(); return 0; < pre> <p> <strong>Output:</strong> </p> <pre> 1 2 3 4 5 6 7 8 9 10 </pre> <p>In the above example, the class template is created which contains the nontype template argument, i.e., size. It is specified when the object of class &apos;A&apos; is created.</p> <p> <strong>Points to Remember</strong> </p> <ul> <li>C++ supports a powerful feature known as a template to implement the concept of generic programming.</li> <li>A template allows us to create a family of classes or family of functions to handle different data types.</li> <li>Template classes and functions eliminate the code duplication of different data types and thus makes the development easier and faster.</li> <li>Multiple parameters can be used in both class and function template.</li> <li>Template functions can also be overloaded.</li> <li>We can also use nontype arguments such as built-in or derived data types as template arguments.</li> </ul> <br></size;j++)></pre></\'></pre></std::endl;></pre></\'value></pre></a<<>

A fenti példában a fun() függvény sablonja túlterhelt.

Az általános funkciók korlátozásai

Az általános függvények ugyanazt a műveletet hajtják végre a függvény összes verziójához, kivéve az adattípusok eltéréseit. Lássunk egy egyszerű példát egy túlterhelt függvényre, amelyet nem lehet helyettesíteni az általános függvénnyel, mivel mindkét függvénynek más-más funkciója van.

Értsük meg ezt egy egyszerű példán keresztül:

 #include using namespace std; void fun(double a) { cout&lt;<\'value of a is : \'< <a<<\'
\'; } void fun(int b) { if(b%2="=0)" cout<<\'number even\'; else odd\'; int main() fun(4.6); fun(6); return 0; < pre> <p> <strong>Output:</strong> </p> <pre> value of a is : 4.6 Number is even </pre> <p>In the above example, we overload the ordinary functions. We cannot overload the generic functions as both the functions have different functionalities. First one is displaying the value and the second one determines whether the number is even or not.</p> <hr> <h2>CLASS TEMPLATE</h2> <p> <strong>Class Template</strong> can also be defined similarly to the Function Template. When a class uses the concept of Template, then the class is known as generic class.</p> <h2>Syntax</h2> <pre> template class class_name { . . } </pre> <p> <strong>Ttype</strong> is a placeholder name which will be determined when the class is instantiated. We can define more than one generic data type using a comma-separated list. The Ttype can be used inside the class body.</p> <p>Now, we create an instance of a class</p> <pre> class_name ob; </pre> <p> <strong>where class_name</strong> : It is the name of the class.</p> <p> <strong>type</strong> : It is the type of the data that the class is operating on.</p> <p> <strong>ob</strong> : It is the name of the object.</p> <p> <strong>Let&apos;s see a simple example:</strong> </p> <pre> #include using namespace std; template class A { public: T num1 = 5; T num2 = 6; void add() { std::cout &lt;&lt; &apos;Addition of num1 and num2 : &apos; &lt;&lt; num1+num2&lt;<std::endl; } }; int main() { a d; d.add(); return 0; < pre> <p> <strong>Output:</strong> </p> <pre> Addition of num1 and num2 : 11 </pre> <p>In the above example, we create a template for class A. Inside the main() method, we create the instance of class A named as, &apos;d&apos;.</p> <h3>CLASS TEMPLATE WITH MULTIPLE PARAMETERS</h3> <p>We can use more than one generic data type in a class template, and each generic data type is separated by the comma.</p> <h2>Syntax</h2> <pre> template class class_name { // Body of the class. } </pre> <p> <strong>Let&apos;s see a simple example when class template contains two generic data types.</strong> </p> <pre> #include using namespace std; template class A { T1 a; T2 b; public: A(T1 x,T2 y) { a = x; b = y; } void display() { std::cout &lt;&lt; &apos;Values of a and b are : &apos; &lt;&lt; a&lt;<\' ,\'< <b<<std::endl; } }; int main() { a d(5,6.5); d.display(); return 0; < pre> <p> <strong>Output:</strong> </p> <pre> Values of a and b are : 5,6.5 </pre> <h3>Nontype Template Arguments</h3> <p>The template can contain multiple arguments, and we can also use the non-type arguments In addition to the type T argument, we can also use other types of arguments such as strings, function names, constant expression and built-in types. <strong>Let&apos; s see the following example:</strong> </p> <pre> template class array { T arr[size]; // automatic array initialization. }; </pre> <p>In the above case, the nontype template argument is size and therefore, template supplies the size of the array as an argument.</p> <p>Arguments are specified when the objects of a class are created:</p> <pre> array t1; // array of 15 integers. array t2; // array of 10 floats. array t3; // array of 4 chars. </pre> <p>Let&apos;s see a simple example of nontype template arguments.</p> <pre> #include using namespace std; template class A { public: T arr[size]; void insert() { int i =1; for (int j=0;j<size;j++) { arr[j]="i;" i++; } void display() for(int i="0;i&lt;size;i++)" std::cout << arr[i] \' \'; }; int main() a t1; t1.insert(); t1.display(); return 0; < pre> <p> <strong>Output:</strong> </p> <pre> 1 2 3 4 5 6 7 8 9 10 </pre> <p>In the above example, the class template is created which contains the nontype template argument, i.e., size. It is specified when the object of class &apos;A&apos; is created.</p> <p> <strong>Points to Remember</strong> </p> <ul> <li>C++ supports a powerful feature known as a template to implement the concept of generic programming.</li> <li>A template allows us to create a family of classes or family of functions to handle different data types.</li> <li>Template classes and functions eliminate the code duplication of different data types and thus makes the development easier and faster.</li> <li>Multiple parameters can be used in both class and function template.</li> <li>Template functions can also be overloaded.</li> <li>We can also use nontype arguments such as built-in or derived data types as template arguments.</li> </ul> <br></size;j++)></pre></\'></pre></std::endl;></pre></\'value>

A fenti példában túlterheljük a közönséges függvényeket. Nem tudjuk túlterhelni az általános függvényeket, mivel mindkét funkciónak más-más funkciója van. Az első az értéket jeleníti meg, a második pedig meghatározza, hogy a szám páros-e vagy sem.

OSZTÁLY SABLON

Osztály sablon a függvénysablonhoz hasonlóan definiálható is. Ha egy osztály a Sablon fogalmát használja, akkor az osztályt általános osztálynak nevezzük.

Szintaxis

 template class class_name { . . } 

Ttype egy helyőrző név, amelyet az osztály példányosításakor határoznak meg. Egynél több általános adattípust is meghatározhatunk vesszővel elválasztott lista használatával. A Ttype az osztálytörzsön belül használható.

Most létrehozunk egy osztály példányát

az absztrakt osztálynak lehet konstruktora

 class_name ob; 

ahol az osztály_neve : Ez az osztály neve.

típus : Azon adatok típusa, amelyeken az osztály dolgozik.

nál nél : Az objektum neve.

Lássunk egy egyszerű példát:

 #include using namespace std; template class A { public: T num1 = 5; T num2 = 6; void add() { std::cout &lt;&lt; &apos;Addition of num1 and num2 : &apos; &lt;&lt; num1+num2&lt;<std::endl; } }; int main() { a d; d.add(); return 0; < pre> <p> <strong>Output:</strong> </p> <pre> Addition of num1 and num2 : 11 </pre> <p>In the above example, we create a template for class A. Inside the main() method, we create the instance of class A named as, &apos;d&apos;.</p> <h3>CLASS TEMPLATE WITH MULTIPLE PARAMETERS</h3> <p>We can use more than one generic data type in a class template, and each generic data type is separated by the comma.</p> <h2>Syntax</h2> <pre> template class class_name { // Body of the class. } </pre> <p> <strong>Let&apos;s see a simple example when class template contains two generic data types.</strong> </p> <pre> #include using namespace std; template class A { T1 a; T2 b; public: A(T1 x,T2 y) { a = x; b = y; } void display() { std::cout &lt;&lt; &apos;Values of a and b are : &apos; &lt;&lt; a&lt;<\' ,\'< <b<<std::endl; } }; int main() { a d(5,6.5); d.display(); return 0; < pre> <p> <strong>Output:</strong> </p> <pre> Values of a and b are : 5,6.5 </pre> <h3>Nontype Template Arguments</h3> <p>The template can contain multiple arguments, and we can also use the non-type arguments In addition to the type T argument, we can also use other types of arguments such as strings, function names, constant expression and built-in types. <strong>Let&apos; s see the following example:</strong> </p> <pre> template class array { T arr[size]; // automatic array initialization. }; </pre> <p>In the above case, the nontype template argument is size and therefore, template supplies the size of the array as an argument.</p> <p>Arguments are specified when the objects of a class are created:</p> <pre> array t1; // array of 15 integers. array t2; // array of 10 floats. array t3; // array of 4 chars. </pre> <p>Let&apos;s see a simple example of nontype template arguments.</p> <pre> #include using namespace std; template class A { public: T arr[size]; void insert() { int i =1; for (int j=0;j<size;j++) { arr[j]="i;" i++; } void display() for(int i="0;i&lt;size;i++)" std::cout << arr[i] \' \'; }; int main() a t1; t1.insert(); t1.display(); return 0; < pre> <p> <strong>Output:</strong> </p> <pre> 1 2 3 4 5 6 7 8 9 10 </pre> <p>In the above example, the class template is created which contains the nontype template argument, i.e., size. It is specified when the object of class &apos;A&apos; is created.</p> <p> <strong>Points to Remember</strong> </p> <ul> <li>C++ supports a powerful feature known as a template to implement the concept of generic programming.</li> <li>A template allows us to create a family of classes or family of functions to handle different data types.</li> <li>Template classes and functions eliminate the code duplication of different data types and thus makes the development easier and faster.</li> <li>Multiple parameters can be used in both class and function template.</li> <li>Template functions can also be overloaded.</li> <li>We can also use nontype arguments such as built-in or derived data types as template arguments.</li> </ul> <br></size;j++)></pre></\'></pre></std::endl;>

A fenti példában létrehozunk egy sablont az A osztályhoz. A main() metóduson belül létrehozzuk az A osztály 'd' nevű példányát.

OSZTÁLY SABLON TÖBB PARAMÉTERREL

Egy osztálysablonban több általános adattípust is használhatunk, és minden általános adattípust vessző választ el.

linux parancsok

Szintaxis

 template class class_name { // Body of the class. } 

Lássunk egy egyszerű példát, amikor az osztálysablon két általános adattípust tartalmaz.

 #include using namespace std; template class A { T1 a; T2 b; public: A(T1 x,T2 y) { a = x; b = y; } void display() { std::cout &lt;&lt; &apos;Values of a and b are : &apos; &lt;&lt; a&lt;<\\' ,\\'< <b<<std::endl; } }; int main() { a d(5,6.5); d.display(); return 0; < pre> <p> <strong>Output:</strong> </p> <pre> Values of a and b are : 5,6.5 </pre> <h3>Nontype Template Arguments</h3> <p>The template can contain multiple arguments, and we can also use the non-type arguments In addition to the type T argument, we can also use other types of arguments such as strings, function names, constant expression and built-in types. <strong>Let&apos; s see the following example:</strong> </p> <pre> template class array { T arr[size]; // automatic array initialization. }; </pre> <p>In the above case, the nontype template argument is size and therefore, template supplies the size of the array as an argument.</p> <p>Arguments are specified when the objects of a class are created:</p> <pre> array t1; // array of 15 integers. array t2; // array of 10 floats. array t3; // array of 4 chars. </pre> <p>Let&apos;s see a simple example of nontype template arguments.</p> <pre> #include using namespace std; template class A { public: T arr[size]; void insert() { int i =1; for (int j=0;j<size;j++) { arr[j]="i;" i++; } void display() for(int i="0;i&lt;size;i++)" std::cout << arr[i] \\' \\'; }; int main() a t1; t1.insert(); t1.display(); return 0; < pre> <p> <strong>Output:</strong> </p> <pre> 1 2 3 4 5 6 7 8 9 10 </pre> <p>In the above example, the class template is created which contains the nontype template argument, i.e., size. It is specified when the object of class &apos;A&apos; is created.</p> <p> <strong>Points to Remember</strong> </p> <ul> <li>C++ supports a powerful feature known as a template to implement the concept of generic programming.</li> <li>A template allows us to create a family of classes or family of functions to handle different data types.</li> <li>Template classes and functions eliminate the code duplication of different data types and thus makes the development easier and faster.</li> <li>Multiple parameters can be used in both class and function template.</li> <li>Template functions can also be overloaded.</li> <li>We can also use nontype arguments such as built-in or derived data types as template arguments.</li> </ul> <br></size;j++)></pre></\\'>

Nem típusú sablon argumentumok

A sablon több argumentumot is tartalmazhat, és használhatjuk a nem típusú argumentumokat is. A T típusú argumentum mellett más típusú argumentumokat is használhatunk, például karakterláncokat, függvényneveket, konstans kifejezéseket és beépített típusokat. Lássuk a következő példát:

 template class array { T arr[size]; // automatic array initialization. }; 

A fenti esetben a nontype template argumentum a méret, ezért a template a tömb méretét adja meg argumentumként.

Az argumentumok az osztály objektumainak létrehozásakor kerülnek megadásra:

 array t1; // array of 15 integers. array t2; // array of 10 floats. array t3; // array of 4 chars. 

Nézzünk egy egyszerű példát a nem típusú sablon argumentumokra.

 #include using namespace std; template class A { public: T arr[size]; void insert() { int i =1; for (int j=0;j<size;j++) { arr[j]="i;" i++; } void display() for(int i="0;i&lt;size;i++)" std::cout << arr[i] \\' \\'; }; int main() a t1; t1.insert(); t1.display(); return 0; < pre> <p> <strong>Output:</strong> </p> <pre> 1 2 3 4 5 6 7 8 9 10 </pre> <p>In the above example, the class template is created which contains the nontype template argument, i.e., size. It is specified when the object of class &apos;A&apos; is created.</p> <p> <strong>Points to Remember</strong> </p> <ul> <li>C++ supports a powerful feature known as a template to implement the concept of generic programming.</li> <li>A template allows us to create a family of classes or family of functions to handle different data types.</li> <li>Template classes and functions eliminate the code duplication of different data types and thus makes the development easier and faster.</li> <li>Multiple parameters can be used in both class and function template.</li> <li>Template functions can also be overloaded.</li> <li>We can also use nontype arguments such as built-in or derived data types as template arguments.</li> </ul> <br></size;j++)>

A fenti példában az osztálysablon jön létre, amely tartalmazza a nontype template argumentumot, azaz a méretet. Az 'A' osztályú objektum létrehozásakor kerül megadásra.

Emlékeztető pontok

• A C++ támogatja az általános programozás koncepcióját megvalósító sablonként ismert hatékony szolgáltatást.
• Egy sablon lehetővé teszi osztályok vagy függvénycsaládok létrehozását a különböző adattípusok kezelésére.
• A sablon osztályok és függvények kiküszöbölik a különböző adattípusok kódduplikációját, így könnyebbé és gyorsabbá teszik a fejlesztést.
• Az osztályban és a függvénysablonban is többféle paraméter használható.
• A sablonfunkciók is túlterhelhetők.
• Használhatunk nem típus argumentumokat is, például beépített vagy származtatott adattípusokat sablon argumentumként.