UINT64_MAX用于返回uint64_t可以包含的最大值一种常见的情况是将双精度转换为 uint64_t。我们会 :
- 确保它被转换为的 uint64_t 变量大于或等于零。
- 它小于或等于 UINT64_MAX (std::numeric_limits 显然也可以。)
这是一个例子:
#include <iostream>
#include <cstdint>
int main() {
constexpr double a = 6383464.632463948;
if (b >= 0 && b <= UINT64_MAX) {
uint64_t b = (uint64_t)a; // Cast the double into the uint64_t variable
std::cout << "Conversion from double to uint64_t is valid" << std::endl;
std::cout << "b value is " << b << std::endl;
}
else {
std::cout << "Conversion from double to uint64_t is not valid" <<
std::endl;
}
}