#include <catch2/catch.hpp>

bool is_about_cxx()
{ // nullary functions (no parameters)
    return true;
}

int square(int const x)
{ // unary functions (one parameter)
    return x * x;
}

int area(int const width, int const length)
{ // binary functions (two parameters)
    return width * length;
}

TEST_CASE()
{
    CHECK(is_about_cxx());
    CHECK(square(2) == 4);
    CHECK(area(2, 4) == 8);
}