Class Template Argument Deduction in C++17

// C++ Program to illustrate the implicitly-generated
// deduction guides in C++17
#include <iostream>

// class template
template <typename T> class MyContainer {
public:
    MyContainer(T value)
    {
        std::cout << "Created MyContainer<"
                  << typeid(T).name()
                  << "> with value: " << value << std::endl;
    }
};

// driver code
int main()
{
    // not specifying the type of the template
    auto container1 = MyContainer(42);
    auto container2 = MyContainer("Hello");

    return 0;
}

// C++ program to demonstrates the usage of user-defined
// deduction guides in C++17
#include <iostream>

// class template
template <typename T> class MyContainer {
public:
    MyContainer(T value)
    {
        std::cout << "Created MyContainer<"
                  << typeid(T).name()
                  << "> with value: " << value << std::endl;
    }
};

// User-defined deduction guide
template <typename T> MyContainer(T) -> MyContainer<T>;

int main()
{
    // creating class template instance
    auto container1 = MyContainer(42);
    auto container2 = MyContainer("Hello");

    return 0;
}

// C++ program to demonstrate the usage of the deduction for
// alias templates:
#include <iostream>

template <typename T> using MyAlias = T;

int main()
{
    MyAlias<int> alias1 = 42;
    MyAlias<char> alias2 = 'A';

    std::cout << "alias1: " << alias1 << std::endl;
    std::cout << "alias2: " << alias2 << std::endl;

    return 0;
}

// C++ program to illustrate the class template argument deduction
#include <iostream>
#include <vector>

using namespace std;

// Define a class template called MyContainer
template <typename T> class MyContainer {
private:
    vector<T> vec; // Private member variable of type vector

public:
    // Constructor of MyContainer class that takes an
    // initializer list
    MyContainer(const initializer_list<T>& list)
        : vec(list)
    {
    }

    // Print function to display the elements of the vector
    void print() const
    {
        for (const auto& val : vec) {
            cout << val << " ";
        }
        cout << endl;
    }
};

int main()
{
    // Create an instance of MyContainer using class
    // template argument deduction
    // introduced in C++17
    auto myContainer = MyContainer({ 1, 2, 3, 4, 5 });

    // Print the elements of the container using the print()
    // function
    myContainer.print();

    return 0;
}