Код: Выделить всё
std::vector v{3, -4, 2, -8, 15, 267};
struct Sum
{
void operator()(int n) { sum += n; }
int sum {0};
};
// invoke Sum::operator() for each element
Sum s = std::for_each(v.cbegin(), v.cend(), Sum());
std::cout
Подробнее здесь: [url]https://stackoverflow.com/questions/78744753/understanding-usage-of-stdfor-each-with-structs[/url]