# std::make_any

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< cpp‎ | utility‎ | any

Defined in header `<any>` |  |
template< class T, class... Args > std::any make_any( Args&&... args ); | (1) | (since C++17)
template< class T, class U, class... Args > std::any make_any( std::initializer_list <U> il, Args&&... args ); | (2) | (since C++17)

Constructs an `any` object containing an object of type `T`, passing the provided arguments to `T`'s constructor.

1) Equivalent to return std::any ( std::in_place_type <T>, std::forward <Args>(args)...);
2) Equivalent to return std::any ( std::in_place_type <T>, il, std::forward <Args>(args)...);

### Example

Run this code

    #include <any>
    #include <complex>
    #include <functional>
    #include <iostream>
    #include <string>

    int main()
    {
        auto a0 = std::make_any<std::string>("Hello, std::any!\n");
        auto a1 = std::make_any<std::complex<double>>(0.1, 2.3);

        std::cout << std::any_cast<std::string&>(a0);
        std::cout << std::any_cast<std::complex<double>&>(a1) << '\n';

        using lambda = std::function<void(void)>;

        // Put a lambda into std::any. Attempt #1 (failed).
        std::any a2 = [] { std::cout << "Lambda #1.\n"; };
        std::cout << "a2.type() = \"" << a2.type().name() << "\"\n";

        // any_cast casts to <void(void)> but actual type is not
        // a std::function..., but ~ main::{lambda()#1}, and it is
        // unique for each lambda. So, this throws...
        try
        {
            std::any_cast<lambda>(a2)();
        }
        catch (std::bad_any_cast const& ex)
        {
            std::cout << ex.what() << '\n';
        }

        // Put a lambda into std::any. Attempt #2 (successful).
        auto a3 = std::make_any<lambda>([] { std::cout << "Lambda #2.\n"; });
        std::cout << "a3.type() = \"" << a3.type().name() << "\"\n";
        std::any_cast<lambda>(a3)();
    }

Possible output:

    Hello, std::any!
    (0.1,2.3)
    a2.type() = "Z4mainEUlvE_"
    bad any_cast
    a3.type() = "St8functionIFvvEE"
    Lambda #2.

### See also

(constructor) | constructs an `any` object (public member function)
any_cast (C++17) | type-safe access to the contained object (function template)

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