Some codes of cpp cannot be rendered

[Vanessa219]

Describe the issue
Some code of cpp can not be rendered.

Which language seems to have the issue?
cpp

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Sample Code to Reproduce

#include <iostream>
#include <Eigen/Core>
int main(int argc, char** argv)
{
    //1.方阵
    Eigen::Matrix3f  A;   //本质是Eigen::Matrix<float,3,3> A;  
    A << 1,2,3,4,5,6,7,8,9;
    std::cout << "A= \n" << A << std::endl;

    //2. 转置操作
    Eigen::Matrix3f  A_T =  A.transpose();
    std::cout << "\nA的转置矩阵A_T= \n" << A_T << std::endl;

    //3. 零矩阵
    Eigen::Matrix<float,3,5> B = Eigen::Matrix<float,3,5>::Zero();
    std::cout << "\nB= \n" << B << std::endl;

    //4. 对角矩阵
    //4.1 构造对角矩阵
    Eigen::VectorXd vector(5);                //构建5维向量
    vector<<1,2,3,4,5;                        //向量赋值
    Eigen::MatrixXd  C(vector.asDiagonal());  //使用向量生成对角阵
    std::cout << "\nC= \n" << C << std::endl;

    //4.2 从普通矩阵中提取对角元素组成向量 
    std::cout << "\n从C中提取对角元素构成向量= \n" << C.diagonal() << std::endl;    //C也可以不是方阵

    //5. 单位矩阵
    //5.1 构造单位矩阵
    Eigen::Matrix3f D = Eigen::Matrix3f::Identity();                    //简写
    Eigen::Matrix<float,4,4> E = Eigen::Matrix<float,4,4>::Identity();  //完整写法
    std::cout << "\n单位矩阵D= \n" << D << std::endl;
    std::cout << "\n单位矩阵E= \n" << E << std::endl;

    //5.2 构造对角线为1的普通矩阵
    Eigen::Matrix<float,3,5> F = Eigen::Matrix<float,3,5>::Identity();
    std::cout << "\n普通对角元素为1的矩阵F= \n" << F << std::endl;

    return 0;
}

Expected behavior

Additional context
Code:

element.innerHTML = hljs.highlight(code, {
                language: "cpp",
                ignoreIllegals: true
            }).value;

[joshgoebel]

@Vanessa219 Could you test or review PR fix?

[Vanessa219]

It works, thank you.