我一直在尝试获取解码后的XML的值，所有3个值。
XML文件如下所示（它有更多的节点，但这只是一个测试预览）

<Response ID="number" Version="2.0">
    <Issuer xmlns=":assertion">
        check1
    </Issuer>
    <Status>
        <StatusCode Value="Success" />
        checkcheck2
    </Status>
    <Assertion ID="somenumber" IssueInstant="datestamp" Version="2.0"
        xmlns="urn:oasis:names:tc:SAML:2.0:assertion">
        <Issuer>
            checkcheckcheck3
        </Issuer>
    </Assertion>
</Response>

我试图以以下方式从“状态”节点中获取值（不要介意包含我不需要的内容，我已经尝试了很多东西，只是暂时保留它们，以防我需要它们，当它工作时将删除它们）：

#include <iostream>
#include <sstream>
#include <iostream>
#include <cstring>
#include <string>
#include <fstream>
#include <vector>
#include "rapidxml.hpp"
#include "rapidxml_print.hpp"
#include "base64.hpp"

using namespace std;
    int main()
    {
        rapidxml::xml_node<> *root_node;
        rapidxml::xml_node<> *second_node;
        
                
        //costum base64 encoder and decoder this works as it should
        help::base64_decode;
    
        string xmlFile;
    
        // Base64 response from form data contains xml
        xmlFile = help::base64_decode("the base64 encoded SAMLResponse");
    
        //put the b64 decoded xml in a string
        stringstream decodedXml(xmlFile);
        rapidxml::xml_document<> doc;
    
        // test the decoded b64
        cout << xmlFile << endl;
    
        // Read file into vector<char>
        vector<char> buffer((istreambuf_iterator<char>(decodedXml)), istreambuf_iterator<char>());
    
        buffer.push_back('\0');
    
        doc.parse<0>(&buffer[0]);
    
        root_node = doc.first_node("Response");
    
    // this returs Issuer 
        cout << root_node->first_node()->name() << endl;
    
    // go to next sibling of the root node ?? (that should be Status)
        second_node = root_node->next_sibling(); 
    
    // gives me a exited with code=3221225477 in 0.485 seconds on compiling 
        cout << second_node->first_node()->name() << endl;

我做错了什么，或者说，我误解了next_sibling()函数的哪一部分。据我所知，next_sibling()将转到与声明为root_node的节点（在本例中是Issuer）处于同一级别的下一个节点。