code: сделал вариант

main.cpp

@@ -35,36 +35,44 @@ input_data(istream &tin, bool prompt){
         cerr << "Input bin count: ";
     tin >> in.bin_count;
     return in;
-}size_t
+}
-write_data(void* items, size_t item_size, size_t item_count, void* ctx) {
+
+size_t write_data(void* items, size_t item_size, size_t item_count, void* ctx) {
     size_t data_size = item_size * item_count;
     stringstream* buffer = reinterpret_cast<stringstream*>(ctx);
     buffer->write(reinterpret_cast<const char*>(items), data_size);
     return data_size;
 }
-
 Input
-download(const string& address) {
+download(const string& address)
+{
     stringstream buffer;
     CURL *curl = curl_easy_init();
     if(curl)
     {
         CURLcode res;
+        curl_off_t speed;
         curl_easy_setopt(curl, CURLOPT_URL, address.c_str());
         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_data);
         curl_easy_setopt(curl, CURLOPT_WRITEDATA, &buffer);
         res = curl_easy_perform(curl);
+
         if (res != CURLE_OK)
         {
             fprintf(stderr, "curl_easy_perform() failed: %s\n",curl_easy_strerror(res));
             exit(1);
         }
+        res = curl_easy_getinfo(curl, CURLINFO_SPEED_DOWNLOAD_T, &speed);
+        if(!res)
+        {
+            cerr<<"Download speed bytes/sec:  " <<speed;
+        }
+
         curl_easy_cleanup(curl);
 
     }
     return input_data(buffer, false);
 }
-
 int
 main(int argc, char* argv[]) {
     Input input;