How do C++ templates work?

Templates in C++ allow writing reusable code with the syntax 2dcb0b4f8fe16599145d6112383b352e that are instantiated when called. Template specializations provide special implementations for specific types. In practice, templates can be used to sort arrays of different types, such as in the insertion sort algorithm.

C++ Templates: In-depth Understanding

Introduction

Templates are powerful in C++ feature that allows writing reusable code without repeating the same functionality for each data type. This article will delve into how C++ templates work and demonstrate their application through practical cases.

Basic template syntax

Templates are written using angle brackets a8093152e673feb7aba1828c43532094, which specify template parameters. For example, here is a template function that exchanges two values ​​of any type:

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

Instantiation

When the template is called, the template parameters are replaced with specific data type. This process is called instantiation. For example, to call the swap function for an integer type:

swap<int>(x, y);

Template Specializations

Template specializations allow different implementations to be provided for specific data types. For example, we can provide an optimized implementation for the char type in the swap function:

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

Practical case: Insertion sort

Consider an insertion sort algorithm using templates:

template <typename T>
void insertionSort(T arr[], int n) {
    for (int i = 1; i < n; i++) {
        T key = arr[i];
        int j = i - 1;
        while (j >= 0 && arr[j] > key) {
            arr[j + 1] = arr[j];
            j--;
        }
        arr[j + 1] = key;
    }
}

This algorithm uses the swap template function to exchange values ​​and can be used to sort arrays of any data type.

Conclusion

C++ templates provide a powerful mechanism for writing efficient and reusable code. By understanding how templates work and through practical examples, we can take advantage of them in a variety of applications.

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