ull or llu
#include <cstdio>
#include <iostream>
int main() {
unsigned long long a = 1000ULL;
printf("a:%llu\n", a);
std::string b = "2000";
std::cout << "std::stoull(b):" << std::stoull(b) << std::endl;
}
输出
a:1000
std::stoull(b):2000
printf中用llu标识unsigned long long，std::stoull中却用ull标识unsigned long long，有点反直觉。
