diff --git a/.vs/ProjectSettings.json b/.vs/ProjectSettings.json
new file mode 100644
index 0000000..899f460
--- /dev/null
+++ b/.vs/ProjectSettings.json
@@ -0,0 +1,3 @@
+{
+  "CurrentProjectSetting": "x86-Debug"
+}
\ No newline at end of file
diff --git a/.vs/Simple-Web-Server/v15/Browse.VC.db b/.vs/Simple-Web-Server/v15/Browse.VC.db
new file mode 100644
index 0000000..833baed
Binary files /dev/null and b/.vs/Simple-Web-Server/v15/Browse.VC.db differ
diff --git a/.vs/Simple-Web-Server/v15/Browse.VC.opendb b/.vs/Simple-Web-Server/v15/Browse.VC.opendb
new file mode 100644
index 0000000..0188e62
Binary files /dev/null and b/.vs/Simple-Web-Server/v15/Browse.VC.opendb differ
diff --git a/.vs/slnx.sqlite b/.vs/slnx.sqlite
new file mode 100644
index 0000000..1d49f8f
Binary files /dev/null and b/.vs/slnx.sqlite differ
diff --git a/client_http.hpp b/client_http.hpp
index baece6f..0832d38 100644
--- a/client_http.hpp
+++ b/client_http.hpp
@@ -16,7 +16,16 @@ namespace SimpleWeb {
   using errc = std::errc;
   using system_error = std::system_error;
   namespace make_error_code = std;
-  using string_view = const std::string &; // TODO c++17: use std::string_view
+#ifdef __has_include 
+  #if __has_include(<string_view>)
+    #include<string_view>
+    using string_view = std::string_view;
+    #define __has_string_view 1
+  #endif
+#endif
+#ifndef __has_string_view
+  using string_view = const std::string &;
+#endif
 } // namespace SimpleWeb
 #else
 #include <boost/asio.hpp>