寻找QT函数将qint64类型的变量(整数)舍入到最近的十

import math

x = 3.1415926
y = math.round(x)
print(y) # 输出3

#include <iostream>
#include <cmath>

int main() {
    double x = 3.1415926;
    int y = std::round(x);
    std::cout << y << std::endl; // 输出3
    return 0;
}

import java.lang.Math;

public class Main {
    public static void main(String[] args) {
        double x = 3.1415926;
        int y = (int) Math.round(x);
        System.out.println(y); // 输出3
    }
}

#include <QString>
#include <QDebug>

int main(int argc, char *argv[]) {
    QString x = "3.1415926";
    QString y = QString::number(x.toDouble()).rightJustified(10, '0');
    qDebug() << y; // 输出3.14
    return 0;
}