From 4f79778ca5296e7be71a54b6debfaae39470c587 Mon Sep 17 00:00:00 2001
From: Keith Winstein <keithw@mit.edu>
Date: Sat, 31 Mar 2012 14:54:16 -0400
Subject: [PATCH] Add warning for C libraries that don't commit to Unicode
 wchar_t

---
 configure.ac | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/configure.ac b/configure.ac
index 929961f..c9748cb 100644
--- a/configure.ac
+++ b/configure.ac
@@ -166,6 +166,11 @@ AC_CHECK_DECL([IP_MTU_DISCOVER],
      [Define if IP_MTU_DISCOVER is a valid sockopt.])],
   , [[#include <netinet/ip.h>]])
 
+AC_CHECK_DECL([__STDC_ISO_10646__],
+  [],
+  [AC_MSG_WARN([C library doesn't advertise wchar_t is Unicode (OS X works anyway with workaround).])],
+  [[#include <wchar.h>]])
+
 # Checks for protobuf
 PKG_CHECK_MODULES([protobuf], [protobuf])