Templates in C++

Templates in C++ allow the programmer to write generic code that can work with a variety of data types. This is achieved by passing a data type as a parameter to the template, which is then used throughout the code. By using templates, the programmer can reduce the amount of code repetition, as the same declaration can be used for different data types, making it a more efficient and flexible approach to programming.

For example, consider a class that contains an integer pointer and an integer variable “size”. This class acts like an array of integers with a given length “size”. This class could be used for different data types such as int, float, or char, but the code would have to be written again and again for each data type. However, by using templates, the programmer can declare the class once and use it for any data type by passing the data type as a parameter.

The syntax of a template in C++ starts with the keyword “template” followed by angle brackets “<” and “>” that contain the type parameter(s). The type parameter(s) can then be used throughout the code to create a generic class or function that can work with different data types.

In summary, C++ templates are a powerful tool for programmers, as they allow for the creation of generic code that can be used with different data types. This results in a more efficient and flexible programming approach and reduces code repetition.

The class in question here consists of two components – an integer pointer and an integer variable named size. This class operates as an array of integers with a specified length, which is determined by the value of the variable “size”. This type of class is commonly referred to as a “vector”.

class vector

{
    int *arr;
    int size;
};

Instead of writing separate classes for arrays of different data types, we can make use of templates in C++ to make a generic class definition that can be applied to arrays of any data type. This way, we can avoid the repetition of the same code for different data types, and save time and effort.

template <class T>

{
    T *arr;
    int size;
};

This is because the template allows us to define the data type of the array as a parameter, which can then be supplied when creating an object of the class. By doing this, we can reuse the same definition of the class for different data types without having to rewrite it. This reduces the amount of repetitive code and makes it easier to maintain.

#include <iostream>
using namespace std;
 
template <class T>
class vector
{
    T *arr;
    int size;
};
 
int main()
{
    vector<int> v1();
    vector<float> v2();
}