diff --git a/include/boost/regex/config.hpp b/include/boost/regex/config.hpp
index cc783a0b..db35fbd3 100644
--- a/include/boost/regex/config.hpp
+++ b/include/boost/regex/config.hpp
@@ -18,10 +18,10 @@
 
 #ifndef BOOST_REGEX_CONFIG_HPP
 #define BOOST_REGEX_CONFIG_HPP
-//
-// Borland C++ Fix/error check
-// this has to go *before* we include any std lib headers:
-//
+/*
+ Borland C++ Fix/error check
+ this has to go *before* we include any std lib headers:
+*/
 #if defined(__BORLANDC__)
 #  include <boost/regex/config/borland.hpp>
 #endif
@@ -60,11 +60,11 @@
 #     include <locale>
 #  endif
 #else
-   //
-   // C build,
-   // don't include <boost/config.hpp> because that may
-   // do C++ specific things in future...
-   //
+   /*
+   * C build,
+   * don't include <boost/config.hpp> because that may
+   * do C++ specific things in future...
+   */
 #  include <stdlib.h>
 #  include <stddef.h>
 #  ifdef _MSC_VER
@@ -81,24 +81,24 @@
 /* Obsolete macro, use BOOST_VERSION instead: */
 #define BOOST_RE_VERSION 320
 
-// fix:
+/* fix: */
 #if defined(_UNICODE) && !defined(UNICODE)
 #define UNICODE
 #endif
 
-//
-// If there isn't good enough wide character support then there will
-// be no wide character regular expressions:
-//
+/*
+* If there isn't good enough wide character support then there will
+* be no wide character regular expressions:
+*/
 #if (defined(BOOST_NO_CWCHAR) || defined(BOOST_NO_CWCTYPE) || defined(BOOST_NO_STD_WSTRING))
 #  if !defined(BOOST_NO_WREGEX)
 #     define BOOST_NO_WREGEX
 #  endif
 #else
 #  if defined(__sgi) && (defined(__SGI_STL_PORT) || defined(_STLPORT_VERSION))
-      // STLPort on IRIX is misconfigured: <cwctype> does not compile
-      // as a temporary fix include <wctype.h> instead and prevent inclusion
-      // of STLPort version of <cwctype>
+      /* STLPort on IRIX is misconfigured: <cwctype> does not compile
+      * as a temporary fix include <wctype.h> instead and prevent inclusion
+      * of STLPort version of <cwctype> */
 #     include <wctype.h>
 #     define __STLPORT_CWCTYPE
 #     define _STLP_CWCTYPE
@@ -110,34 +110,34 @@
 
 #endif
 
-//
-// If Win32 support has been disabled for boost in general, then
-// it is for regex in particular:
-//
+/*
+* If Win32 support has been disabled for boost in general, then
+* it is for regex in particular:
+*/
 #if defined(BOOST_DISABLE_WIN32) && !defined(BOOST_REGEX_NO_W32)
 #  define BOOST_REGEX_NO_W32
 #endif
 
-// some versions of gcc can't merge template instances:
+/* some versions of gcc can't merge template instances: */
 #if defined(__CYGWIN__)
 #  define BOOST_REGEX_NO_TEMPLATE_SWITCH_MERGE
 #endif
 
-// fix problems with bool as a macro,
-// this probably doesn't affect any current compilers:
+/* fix problems with bool as a macro,
+* this probably doesn't affect any current compilers: */
 #if defined(bool) || defined(true) || defined(false)
 #  define BOOST_REGEX_NO_BOOL
 #endif
 
-// We don't make our templates external if the compiler
-// can't handle it:
+/* We don't make our templates external if the compiler
+ can't handle it: */
 #if (defined(BOOST_NO_MEMBER_FUNCTION_SPECIALIZATIONS) || defined(__HP_aCC) || defined(__MWERKS__) || defined(__COMO__) || defined(BOOST_INTEL))\
    && !defined(BOOST_MSVC) && !defined(__BORLANDC__)
 #  define BOOST_REGEX_NO_EXTERNAL_TEMPLATES
 #endif
 
-// disable our own file-iterators and mapfiles if we can't
-// support them:
+/* disable our own file-iterators and mapfiles if we can't
+ support them: */
 #if !defined(BOOST_HAS_DIRENT_H) && !(defined(_WIN32) && !defined(BOOST_REGEX_NO_W32))
 #  define BOOST_REGEX_NO_FILEITER
 #endif
diff --git a/include/boost/regex/v4/cregex.hpp b/include/boost/regex/v4/cregex.hpp
index 903aa165..c1313e37 100644
--- a/include/boost/regex/v4/cregex.hpp
+++ b/include/boost/regex/v4/cregex.hpp
@@ -252,8 +252,11 @@ public:
    std::string What(int i = 0)const;
    std::string operator[](int i)const { return What(i); }
 
+#ifdef __MINGW32__
+   static const std::size_t npos = ~0u;
+#else
    static const std::size_t npos;
-
+#endif
    friend struct re_detail::pred1;
    friend struct re_detail::pred2;
    friend struct re_detail::pred3;