From 3704b9c59525dffe91acec6d7d69932bee9b6405 Mon Sep 17 00:00:00 2001
From: John Maddock <john@johnmaddock.co.uk>
Date: Mon, 28 Apr 2008 11:07:14 +0000
Subject: [PATCH] Fixes for issue #1871 that prevents duplicate symbol errors
 with VC++ compilers, when building with /Zc:wchar_t-.

[SVN r44842]
---
 src/usinstances.cpp     |  3 +++
 src/wc_regex_traits.cpp | 33 ++++++++++++++++++++++++++++++++-
 2 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/src/usinstances.cpp b/src/usinstances.cpp
index 337d815f..d9f600dc 100644
--- a/src/usinstances.cpp
+++ b/src/usinstances.cpp
@@ -49,6 +49,9 @@ template _CRTIMP2 bool __cdecl operator>(
 #if BOOST_WORKAROUND(BOOST_MSVC, > 1300) && BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1400))
 template<> _CRTIMP2 std::size_t __cdecl char_traits<unsigned short>::length(unsigned short const*);
 #endif
+#if BOOST_WORKAROUND(BOOST_MSVC, >= 1400)
+template _CRTIMP2 allocator<unsigned short>::allocator();
+#endif
 }
 #endif
 
diff --git a/src/wc_regex_traits.cpp b/src/wc_regex_traits.cpp
index 9daf0804..29a77e15 100644
--- a/src/wc_regex_traits.cpp
+++ b/src/wc_regex_traits.cpp
@@ -19,9 +19,40 @@
 
 #define BOOST_REGEX_SOURCE
 
-#include <boost/config.hpp>
+#include <boost/regex/config.hpp>
 #include <boost/detail/workaround.hpp>
 
+#ifdef _DLL_CPPLIB
+//
+// This is a horrible workaround, without declaring these symbols extern we get
+// duplicate symbol errors when linking if the application is built without
+// /Zc:wchar_t
+//
+namespace std{
+template _CRTIMP2 bool __cdecl operator==(
+   const basic_string<unsigned short, char_traits<unsigned short>, allocator<unsigned short> >&,
+   const basic_string<unsigned short, char_traits<unsigned short>, allocator<unsigned short> >&);
+template _CRTIMP2 bool __cdecl operator==(
+   const unsigned short *,
+   const basic_string<unsigned short, char_traits<unsigned short>, allocator<unsigned short> >&);
+template _CRTIMP2 bool __cdecl operator==(
+   const basic_string<unsigned short, char_traits<unsigned short>, allocator<unsigned short> >&,
+   const unsigned short *);
+template _CRTIMP2 bool __cdecl operator<(
+   const basic_string<unsigned short, char_traits<unsigned short>, allocator<unsigned short> >&,
+   const basic_string<unsigned short, char_traits<unsigned short>, allocator<unsigned short> >&);
+template _CRTIMP2 bool __cdecl operator>(
+   const basic_string<unsigned short, char_traits<unsigned short>, allocator<unsigned short> >&,
+   const basic_string<unsigned short, char_traits<unsigned short>, allocator<unsigned short> >&);
+#if BOOST_WORKAROUND(BOOST_MSVC, > 1300) && BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1400))
+template<> _CRTIMP2 std::size_t __cdecl char_traits<unsigned short>::length(unsigned short const*);
+#endif
+#if BOOST_WORKAROUND(BOOST_MSVC, >= 1400)
+template _CRTIMP2 allocator<unsigned short>::allocator();
+#endif
+}
+#endif
+
 #if !BOOST_WORKAROUND(__BORLANDC__, < 0x560)
 
 #include <boost/regex/v4/c_regex_traits.hpp>