Compilare: main.cpp: In function 'auto primes_until(int)': main.cpp:17:38: warning: comparison of integer expressions of different signedness: 'size_t' {aka 'long unsigned int'} and 'int' [-Wsign-compare] 17 | for (size_t j = i * i; j <= limit; j += i) | ~~^~~~~~~~ main.cpp: In function 'int main()': main.cpp:92:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17' 92 | auto [num_div, sum_div] = solve(primes, x); | ^