Creating Your First Template in C++

Let's see what is happening when we specify different types for the template. For this we will use typeid().name(), it simply shows the data type of the variable. Look at the example below:

main


              1234567
            
#include <iostream>

int main()
{
    int x = 5;
    std::cout << typeid(x).name();    
}

Note

The code snippet above will just display in console i, symbolizing that x is an int.

Let's create a template using <typename Type> and pass Type as a parameter to the function instead of specifying a specific variable.

main


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#include <iostream>

template<typename Type>
void check_type() 
{ 
    std::cout << typeid(Type).name() << std::endl;
}

int main()
{
    // Try to change `int` to different type
    check_type<int>();
}

As you can see, when you call the template function and specify a type within the brackets, the typename parameter receives that type. The name of the template parameter essentially becomes an alias for that type.

Opgave

Swipe to start coding

Turn the swap function into a template function:
1. define template using the template keyword;
2. add the list of template parameters;
3. add one parameter for the template.
Change all types (int) to the typename from the template parameter.
Call the template function and pass char as the type, swapping two variables in the main function.

Løsning

solution

Skift til skrivebord for at øve i den virkelige verdenFortsæt der, hvor du er, med en af nedenstående muligheder

Var alt klart?

Tak for dine kommentarer!

Sektion 1. Kapitel 3

Creating Your First Template in C++

Let's see what is happening when we specify different types for the template. For this we will use typeid().name(), it simply shows the data type of the variable. Look at the example below:

main


              1234567
            
#include <iostream>

int main()
{
    int x = 5;
    std::cout << typeid(x).name();    
}

Note

The code snippet above will just display in console i, symbolizing that x is an int.

Let's create a template using <typename Type> and pass Type as a parameter to the function instead of specifying a specific variable.

main


              12345678910111213
            
#include <iostream>

template<typename Type>
void check_type() 
{ 
    std::cout << typeid(Type).name() << std::endl;
}

int main()
{
    // Try to change `int` to different type
    check_type<int>();
}

Opgave

Swipe to start coding

Turn the swap function into a template function:
1. define template using the template keyword;
2. add the list of template parameters;
3. add one parameter for the template.
Change all types (int) to the typename from the template parameter.
Call the template function and pass char as the type, swapping two variables in the main function.

Løsning

solution

Skift til skrivebord for at øve i den virkelige verdenFortsæt der, hvor du er, med en af nedenstående muligheder

Var alt klart?

Tak for dine kommentarer!

Sektion 1. Kapitel 3

Skift til skrivebord for at øve i den virkelige verdenFortsæt der, hvor du er, med en af nedenstående muligheder