Fixed build errors

example/simplesvr.cc

@@ -46,10 +46,7 @@ string dump_multipart_files(const MultipartFiles &files) {
     snprintf(buf, sizeof(buf), "content type: %s\n", file.content_type.c_str());
     s += buf;
 
-    snprintf(buf, sizeof(buf), "text offset: %lu\n", file.offset);
-    s += buf;
-
-    snprintf(buf, sizeof(buf), "text length: %lu\n", file.length);
+    snprintf(buf, sizeof(buf), "text length: %lu\n", file.content.size());
     s += buf;
 
     s += "----------------\n";

example/upload.cc

@@ -37,10 +37,10 @@ int main(void) {
 
   svr.Post("/post", [](const Request & req, Response &res) {
     auto file = req.get_file_value("file");
-    cout << "file: " << file.offset << ":" << file.length << ":" << file.filename << endl;
+    cout << "file length: " << file.content.length() << ":" << file.filename << endl;
 
     ofstream ofs(file.filename, ios::binary);
-    ofs << req.body.substr(file.offset, file.length);
+    ofs << file.content;
 
     res.set_content("done", "text/plain");
   });