Test program using boost::hana::any_of function

Test program using boost::hana::any_of function

When using the boost::hana library in the C++ Boost library, we can use the function boost::hana::any_of provided in it to determine whether any element in the collection meets a specific condition. This function returns a Boolean value indicating whether the collection contains at least one element that satisfies the condition.

The following is a specific sample program that shows how to use the boost::hana::any_of function to find whether any element in an integer set is odd.

#include <boost/hana.hpp>
#include <iostream>

namespace hana = boost::hana;

int main() {
    constexpr auto ints = hana::make_tuple(0, 2, 4, 6, 8, 10);
    std::cout << "Any odd integers in the tuple? ";
    if (hana::any_of(ints, [](auto i) { return i % 2 != 0; })) {
        std::cout << "Yes\n";
    } else {
        std::cout << "No\n";
    }
    return 0;
}

In the above sample program, first use the boost::hana::make_tuple function to create an integer set, which contains 6 even numbers. Then, use the boost::hana::any_of function to search the collection, passing in a Lambda expression as the condition. Determine whether the element is an odd number according to whether the result of the modulus of each element in the Lambda expression is equal to 0.

When running the above program, the console output will display: "Any odd integers in the tuple? No", indicating that there is no odd element in the set.

It is very convenient to use the boost::hana::any_of function, without using loops or manually searching the collection to determine whether there is an element that satisfies the condition. One line of code can do it!