c++ - libcurl uninitialized variable curl error -

i trying make http request retrieve json data; error curl variable not initialized though easy_init() it. on how go around error kind!!

below code:

#pragma once #include "stdafx.h" #include "requestjson.h" #include <string.h> #include <include/curl/curl.h> #include <fstream> #include <iostream> #include <sstream>    using namespace std; class requestjson { public:      static std::string requestjsonstring(std::string url)     {         //set json response on listed loans; open csv file , read unemployment , other indices.          ::curl *curl;         curlcode res;         struct curl_slist *headers = null;         std::ostringstream oss;          //curl_global_init(curl_global_all);         curl = curl_easy_init();         curl_slist_append(headers, "accept: application/json");         curl_slist_append(headers, "content-type: application/json");         curl_easy_cleanup(curl);                  if (curl)         {              curl_easy_setopt(curl, curlopt_httpheader, headers);             curl_easy_setopt(curl, curlopt_url, url.c_str());             curl_easy_setopt(curl, curlopt_httpget, 1);             curl_easy_setopt(curl, curlopt_httpheader, headers);             curl_easy_setopt(curl, curlopt_writefunction, writer); //define write-function below.              res = curl_easy_perform(curl);             if (curle_ok == res)             {                 char *ct;                 res = curl_easy_getinfo(curl, curlinfo_content_type, &ct);                 if ((curle_ok == res) && ct)                     {                     return *downloadedresponse;                     }             }         }     }      //parse json string , return downloaded string.      static std::string *downloadedresponse;     static int writer(char *data, size_t size, size_t nmemb, std::string *buffer_in)     {         if (buffer_in != null)         {             buffer_in->append(data, size * nmemb);             downloadedresponse = buffer_in;             return size * nmemb;         }          return 0;     }   }; 

from the curl_easy_cleanup reference:

this function must the last function call easy session. opposite of curl_easy_init function , must called same handle input curl_easy_init call returned.

_{[emphasis mine]}

when call curl_easy_cleanup cleans up resources allocated curl_easy_init. after can't use curl pointer more.

as reference says: put last, when you're done.