diff --git a/include/boost/regex/config.hpp b/include/boost/regex/config.hpp
index 0db63f84..5d58b733 100644
--- a/include/boost/regex/config.hpp
+++ b/include/boost/regex/config.hpp
@@ -23,6 +23,10 @@
 #  define BOOST_REGEX_CXX03
 #endif
 
+#if defined(BOOST_REGEX_RECURSIVE) && !defined(BOOST_REGEX_CXX03)
+#  define BOOST_REGEX_CXX03
+#endif
+
 #if defined(__has_include)
 #if !defined(BOOST_REGEX_STANDALONE) && !__has_include(<boost/version.hpp>)
 #define BOOST_REGEX_STANDALONE
@@ -374,21 +378,6 @@ BOOST_REGEX_DECL void BOOST_REGEX_CALL reset_stack_guard_page();
 #endif
 
 
-/*****************************************************************************
- *
- *  helper memory allocation functions:
- *
- ****************************************************************************/
-
-#if defined(__cplusplus) && defined(BOOST_REGEX_NON_RECURSIVE)
-namespace boost{ namespace BOOST_REGEX_DETAIL_NS{
-
-BOOST_REGEX_DECL void* BOOST_REGEX_CALL get_mem_block();
-BOOST_REGEX_DECL void BOOST_REGEX_CALL put_mem_block(void*);
-
-}} /* namespaces */
-#endif
-
 /*****************************************************************************
  *
  *  Diagnostics:
diff --git a/include/boost/regex/pattern_except.hpp b/include/boost/regex/pattern_except.hpp
index c61c9bac..e39553ea 100644
--- a/include/boost/regex/pattern_except.hpp
+++ b/include/boost/regex/pattern_except.hpp
@@ -27,8 +27,10 @@
 #include <stdexcept>
 #ifdef BOOST_REGEX_CXX03
 #include <boost/regex/v4/error_type.hpp>
+#include <boost/regex/v4/regex_traits_defaults.hpp>
 #else
 #include <boost/regex/v5/error_type.hpp>
+#include <boost/regex/v5/regex_traits_defaults.hpp>
 #endif
 
 namespace boost{
@@ -51,17 +53,32 @@ namespace boost{
 #pragma warning(disable : 26812)
 #endif
 #endif
-class BOOST_REGEX_DECL regex_error : public std::runtime_error
+class regex_error : public std::runtime_error
 {
 public:
-   explicit regex_error(const std::string& s, regex_constants::error_type err = regex_constants::error_unknown, std::ptrdiff_t pos = 0);
-   explicit regex_error(regex_constants::error_type err);
-   ~regex_error() BOOST_NOEXCEPT_OR_NOTHROW BOOST_OVERRIDE;
+   explicit regex_error(const std::string& s, regex_constants::error_type err = regex_constants::error_unknown, std::ptrdiff_t pos = 0)
+      : std::runtime_error(s)
+      , m_error_code(err)
+      , m_position(pos)
+   {
+   }
+   explicit regex_error(regex_constants::error_type err)
+      : std::runtime_error(::boost::BOOST_REGEX_DETAIL_NS::get_default_error_string(err))
+      , m_error_code(err)
+      , m_position(0)
+   {
+   }
+   ~regex_error() BOOST_NOEXCEPT_OR_NOTHROW BOOST_OVERRIDE {}
    regex_constants::error_type code()const
    { return m_error_code; }
    std::ptrdiff_t position()const
    { return m_position; }
-   void raise()const;
+   void raise()const 
+   {
+#ifndef BOOST_NO_EXCEPTIONS
+      ::boost::throw_exception(*this);
+#endif
+   }
 private:
    regex_constants::error_type m_error_code;
    std::ptrdiff_t m_position;
@@ -72,7 +89,10 @@ typedef regex_error bad_expression;
 
 namespace BOOST_REGEX_DETAIL_NS{
 
-BOOST_REGEX_DECL void BOOST_REGEX_CALL raise_runtime_error(const std::runtime_error& ex);
+inline void BOOST_REGEX_CALL raise_runtime_error(const std::runtime_error& ex)
+{
+   ::boost::throw_exception(ex);
+}
 
 template <class traits>
 void raise_error(const traits& t, regex_constants::error_type code)
diff --git a/include/boost/regex/v4/mem_block_cache.hpp b/include/boost/regex/v4/mem_block_cache.hpp
index 50af421e..1996a512 100644
--- a/include/boost/regex/v4/mem_block_cache.hpp
+++ b/include/boost/regex/v4/mem_block_cache.hpp
@@ -69,6 +69,12 @@ struct mem_block_cache
      }
      ::operator delete(ptr);
    }
+
+   static mem_block_cache& instance()
+   {
+      static mem_block_cache block_cache = { { {nullptr} } };
+      return block_cache;
+   }
 };
 
 
@@ -129,11 +135,43 @@ struct mem_block_cache
          ++cached_blocks;
       }
    }
+   static mem_block_cache& instance()
+   {
+#ifdef BOOST_HAS_THREADS
+      static mem_block_cache block_cache = { 0, 0, BOOST_STATIC_MUTEX_INIT, };
+#else
+      static mem_block_cache block_cache = { 0, 0, };
+#endif
+      return block_cache;
+   }
 };
 #endif
 
-extern mem_block_cache block_cache;
+#if BOOST_REGEX_MAX_CACHE_BLOCKS == 0
 
+inline void* BOOST_REGEX_CALL get_mem_block()
+{
+   return ::operator new(BOOST_REGEX_BLOCKSIZE);
+}
+
+inline void BOOST_REGEX_CALL put_mem_block(void* p)
+{
+   ::operator delete(p);
+}
+
+#else
+
+inline void* BOOST_REGEX_CALL get_mem_block()
+{
+   return mem_block_cache::instance().get();
+}
+
+inline void BOOST_REGEX_CALL put_mem_block(void* p)
+{
+   mem_block_cache::instance().put(p);
+}
+
+#endif
 }
 } // namespace boost
 
diff --git a/include/boost/regex/v4/perl_matcher.hpp b/include/boost/regex/v4/perl_matcher.hpp
index 7d04ff26..4bd7d114 100644
--- a/include/boost/regex/v4/perl_matcher.hpp
+++ b/include/boost/regex/v4/perl_matcher.hpp
@@ -45,7 +45,17 @@ namespace BOOST_REGEX_DETAIL_NS{
 //
 // error checking API:
 //
-BOOST_REGEX_DECL void BOOST_REGEX_CALL verify_options(boost::regex_constants::syntax_option_type ef, match_flag_type mf);
+inline void BOOST_REGEX_CALL verify_options(boost::regex_constants::syntax_option_type, match_flag_type mf)
+{
+   //
+   // can't mix match_extra with POSIX matching rules:
+   //
+   if ((mf & match_extra) && (mf & match_posix))
+   {
+      std::logic_error msg("Usage Error: Can't mix regular expression captures with POSIX matching rules");
+      throw_exception(msg);
+   }
+}
 //
 // function can_start:
 //
diff --git a/include/boost/regex/v4/perl_matcher_non_recursive.hpp b/include/boost/regex/v4/perl_matcher_non_recursive.hpp
index 7e3dce89..1042e794 100644
--- a/include/boost/regex/v4/perl_matcher_non_recursive.hpp
+++ b/include/boost/regex/v4/perl_matcher_non_recursive.hpp
@@ -20,7 +20,7 @@
 #ifndef BOOST_REGEX_V4_PERL_MATCHER_NON_RECURSIVE_HPP
 #define BOOST_REGEX_V4_PERL_MATCHER_NON_RECURSIVE_HPP
 
-#include <new>
+#include <boost/regex/v4/mem_block_cache.hpp>
 
 #ifdef BOOST_MSVC
 #pragma warning(push)
diff --git a/include/boost/regex/v4/regex_traits_defaults.hpp b/include/boost/regex/v4/regex_traits_defaults.hpp
index 38f1d198..2a6c0d12 100644
--- a/include/boost/regex/v4/regex_traits_defaults.hpp
+++ b/include/boost/regex/v4/regex_traits_defaults.hpp
@@ -31,6 +31,7 @@
 #endif
 
 #include <boost/regex/config.hpp>
+#include <boost/cstdint.hpp>
 
 #ifndef BOOST_REGEX_SYNTAX_TYPE_HPP
 #include <boost/regex/v5/syntax_type.hpp>
@@ -38,6 +39,7 @@
 #ifndef BOOST_REGEX_ERROR_TYPE_HPP
 #include <boost/regex/v5/error_type.hpp>
 #endif
+#include <boost/regex/v5/regex_workaround.hpp>
 #include <boost/type_traits/make_unsigned.hpp>
 #include <boost/utility/enable_if.hpp>
 
diff --git a/include/boost/regex/v5/mem_block_cache.hpp b/include/boost/regex/v5/mem_block_cache.hpp
index 50af421e..1996a512 100644
--- a/include/boost/regex/v5/mem_block_cache.hpp
+++ b/include/boost/regex/v5/mem_block_cache.hpp
@@ -69,6 +69,12 @@ struct mem_block_cache
      }
      ::operator delete(ptr);
    }
+
+   static mem_block_cache& instance()
+   {
+      static mem_block_cache block_cache = { { {nullptr} } };
+      return block_cache;
+   }
 };
 
 
@@ -129,11 +135,43 @@ struct mem_block_cache
          ++cached_blocks;
       }
    }
+   static mem_block_cache& instance()
+   {
+#ifdef BOOST_HAS_THREADS
+      static mem_block_cache block_cache = { 0, 0, BOOST_STATIC_MUTEX_INIT, };
+#else
+      static mem_block_cache block_cache = { 0, 0, };
+#endif
+      return block_cache;
+   }
 };
 #endif
 
-extern mem_block_cache block_cache;
+#if BOOST_REGEX_MAX_CACHE_BLOCKS == 0
 
+inline void* BOOST_REGEX_CALL get_mem_block()
+{
+   return ::operator new(BOOST_REGEX_BLOCKSIZE);
+}
+
+inline void BOOST_REGEX_CALL put_mem_block(void* p)
+{
+   ::operator delete(p);
+}
+
+#else
+
+inline void* BOOST_REGEX_CALL get_mem_block()
+{
+   return mem_block_cache::instance().get();
+}
+
+inline void BOOST_REGEX_CALL put_mem_block(void* p)
+{
+   mem_block_cache::instance().put(p);
+}
+
+#endif
 }
 } // namespace boost
 
diff --git a/include/boost/regex/v5/perl_matcher.hpp b/include/boost/regex/v5/perl_matcher.hpp
index e61b3de2..fc0b7b4a 100644
--- a/include/boost/regex/v5/perl_matcher.hpp
+++ b/include/boost/regex/v5/perl_matcher.hpp
@@ -45,7 +45,17 @@ namespace BOOST_REGEX_DETAIL_NS{
 //
 // error checking API:
 //
-BOOST_REGEX_DECL void BOOST_REGEX_CALL verify_options(boost::regex_constants::syntax_option_type ef, match_flag_type mf);
+inline void BOOST_REGEX_CALL verify_options(boost::regex_constants::syntax_option_type, match_flag_type mf)
+{
+   //
+   // can't mix match_extra with POSIX matching rules:
+   //
+   if ((mf & match_extra) && (mf & match_posix))
+   {
+      std::logic_error msg("Usage Error: Can't mix regular expression captures with POSIX matching rules");
+      throw_exception(msg);
+   }
+}
 //
 // function can_start:
 //
@@ -407,10 +417,6 @@ private:
 
    bool find_imp();
    bool match_imp();
-#ifdef BOOST_REGEX_HAS_MS_STACK_GUARD
-   typedef bool (perl_matcher::*protected_proc_type)();
-   bool protected_call(protected_proc_type);
-#endif
    void estimate_max_state_count(std::random_access_iterator_tag*);
    void estimate_max_state_count(void*);
    bool match_prefix();
diff --git a/include/boost/regex/v5/perl_matcher_common.hpp b/include/boost/regex/v5/perl_matcher_common.hpp
index 06710868..d6c2d028 100644
--- a/include/boost/regex/v5/perl_matcher_common.hpp
+++ b/include/boost/regex/v5/perl_matcher_common.hpp
@@ -178,27 +178,10 @@ inline void perl_matcher<BidiIterator, Allocator, traits>::estimate_max_state_co
    max_state_count = BOOST_REGEX_MAX_STATE_COUNT;
 }
 
-#ifdef BOOST_REGEX_HAS_MS_STACK_GUARD
-template <class BidiIterator, class Allocator, class traits>
-inline bool perl_matcher<BidiIterator, Allocator, traits>::protected_call(
-   protected_proc_type proc)
-{
-   ::boost::BOOST_REGEX_DETAIL_NS::concrete_protected_call
-      <perl_matcher<BidiIterator, Allocator, traits> >
-      obj(this, proc);
-   return obj.execute();
-
-}
-#endif
-
 template <class BidiIterator, class Allocator, class traits>
 inline bool perl_matcher<BidiIterator, Allocator, traits>::match()
 {
-#ifdef BOOST_REGEX_HAS_MS_STACK_GUARD
-   return protected_call(&perl_matcher<BidiIterator, Allocator, traits>::match_imp);
-#else
    return match_imp();
-#endif
 }
 
 template <class BidiIterator, class Allocator, class traits>
@@ -242,11 +225,7 @@ bool perl_matcher<BidiIterator, Allocator, traits>::match_imp()
 template <class BidiIterator, class Allocator, class traits>
 inline bool perl_matcher<BidiIterator, Allocator, traits>::find()
 {
-#ifdef BOOST_REGEX_HAS_MS_STACK_GUARD
-   return protected_call(&perl_matcher<BidiIterator, Allocator, traits>::find_imp);
-#else
    return find_imp();
-#endif
 }
 
 template <class BidiIterator, class Allocator, class traits>
diff --git a/include/boost/regex/v5/perl_matcher_non_recursive.hpp b/include/boost/regex/v5/perl_matcher_non_recursive.hpp
index 7e3dce89..8f264e46 100644
--- a/include/boost/regex/v5/perl_matcher_non_recursive.hpp
+++ b/include/boost/regex/v5/perl_matcher_non_recursive.hpp
@@ -20,7 +20,7 @@
 #ifndef BOOST_REGEX_V4_PERL_MATCHER_NON_RECURSIVE_HPP
 #define BOOST_REGEX_V4_PERL_MATCHER_NON_RECURSIVE_HPP
 
-#include <new>
+#include <boost/regex/v5/mem_block_cache.hpp>
 
 #ifdef BOOST_MSVC
 #pragma warning(push)
diff --git a/include/boost/regex/v5/protected_call.hpp b/include/boost/regex/v5/protected_call.hpp
deleted file mode 100644
index 451b2e34..00000000
--- a/include/boost/regex/v5/protected_call.hpp
+++ /dev/null
@@ -1,83 +0,0 @@
-/*
- *
- * Copyright (c) 2004
- * John Maddock
- *
- * Use, modification and distribution are subject to the 
- * Boost Software License, Version 1.0. (See accompanying file 
- * LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
- *
- */
-
- /*
-  *   LOCATION:    see http://www.boost.org for most recent version.
-  *   FILE         basic_regex_creator.cpp
-  *   VERSION      see <boost/version.hpp>
-  *   DESCRIPTION: Declares template class basic_regex_creator which fills in
-  *                the data members of a regex_data object.
-  */
-
-#ifndef BOOST_REGEX_V4_PROTECTED_CALL_HPP
-#define BOOST_REGEX_V4_PROTECTED_CALL_HPP
-
-#include <boost/config.hpp>
-
-#ifdef BOOST_MSVC
-#pragma warning(push)
-#pragma warning(disable: 4103)
-#endif
-#ifdef BOOST_HAS_ABI_HEADERS
-#  include BOOST_ABI_PREFIX
-#endif
-#ifdef BOOST_MSVC
-#pragma warning(pop)
-#endif
-
-namespace boost{
-namespace BOOST_REGEX_DETAIL_NS{
-
-class BOOST_REGEX_DECL abstract_protected_call
-{
-public:
-   bool BOOST_REGEX_CALL execute()const;
-   // this stops gcc-4 from complaining:
-   virtual ~abstract_protected_call(){}
-private:
-   virtual bool call()const = 0;
-};
-
-template <class T>
-class concrete_protected_call
-   : public abstract_protected_call
-{
-public:
-   typedef bool (T::*proc_type)();
-   concrete_protected_call(T* o, proc_type p)
-      : obj(o), proc(p) {}
-private:
-   bool call()const BOOST_OVERRIDE;
-   T* obj;
-   proc_type proc;
-};
-
-template <class T>
-bool concrete_protected_call<T>::call()const
-{
-   return (obj->*proc)();
-}
-
-}
-} // namespace boost
-
-#ifdef BOOST_MSVC
-#pragma warning(push)
-#pragma warning(disable: 4103)
-#endif
-#ifdef BOOST_HAS_ABI_HEADERS
-#  include BOOST_ABI_SUFFIX
-#endif
-#ifdef BOOST_MSVC
-#pragma warning(pop)
-#endif
-
-#endif
diff --git a/include/boost/regex/v5/regex.hpp b/include/boost/regex/v5/regex.hpp
index 9196b04b..7a1ee4bf 100644
--- a/include/boost/regex/v5/regex.hpp
+++ b/include/boost/regex/v5/regex.hpp
@@ -81,9 +81,6 @@
 #ifndef BOOST_REGEX_V4_MATCH_RESULTS_HPP
 #include <boost/regex/v5/match_results.hpp>
 #endif
-#ifndef BOOST_REGEX_V4_PROTECTED_CALL_HPP
-#include <boost/regex/v5/protected_call.hpp>
-#endif
 #ifndef BOOST_REGEX_MATCHER_HPP
 #include <boost/regex/v5/perl_matcher.hpp>
 #endif
diff --git a/include/boost/regex/v5/regex_traits_defaults.hpp b/include/boost/regex/v5/regex_traits_defaults.hpp
index 38f1d198..7eaf31f3 100644
--- a/include/boost/regex/v5/regex_traits_defaults.hpp
+++ b/include/boost/regex/v5/regex_traits_defaults.hpp
@@ -38,8 +38,10 @@
 #ifndef BOOST_REGEX_ERROR_TYPE_HPP
 #include <boost/regex/v5/error_type.hpp>
 #endif
+#include <boost/regex/v5/regex_workaround.hpp>
 #include <boost/type_traits/make_unsigned.hpp>
 #include <boost/utility/enable_if.hpp>
+#include <boost/cstdint.hpp>
 
 #ifdef BOOST_NO_STDC_NAMESPACE
 namespace std{
diff --git a/src/regex.cpp b/src/regex.cpp
index ee0204cc..2d923955 100644
--- a/src/regex.cpp
+++ b/src/regex.cpp
@@ -19,15 +19,12 @@
 
 #define BOOST_REGEX_SOURCE
 
-#include <boost/config.hpp>
-#include <new>
-#include <boost/regex.hpp>
-#include <boost/throw_exception.hpp>
+#include <boost/regex/config.hpp>
 
-#if defined(BOOST_REGEX_HAS_MS_STACK_GUARD) && defined(_MSC_VER) && (_MSC_VER >= 1300)
-#  include <malloc.h>
-#endif
 #ifdef BOOST_REGEX_HAS_MS_STACK_GUARD
+
+#include <malloc.h>
+
 #ifndef WIN32_LEAN_AND_MEAN
 #  define WIN32_LEAN_AND_MEAN
 #endif
@@ -37,78 +34,12 @@
 #define NOGDI
 #define NOUSER
 #include <windows.h>
-#endif
+#include <stdexcept>
+#include <boost/regex/pattern_except.hpp>
+#include <boost/regex/v4/protected_call.hpp>
 
-#if defined(BOOST_REGEX_NON_RECURSIVE) && !defined(BOOST_REGEX_V3)
-#if BOOST_REGEX_MAX_CACHE_BLOCKS == 0
-#include <new>
-#else
-#include <boost/regex/v4/mem_block_cache.hpp>
-#endif
-#endif
-
-#ifdef BOOST_INTEL
-#pragma warning(disable:383)
-#endif
-
-namespace boost{
-
-//
-// fix: these are declared out of line here to ensure
-// that dll builds contain the Virtual table for these
-// types - this ensures that exceptions can be thrown
-// from the dll and caught in an exe.
-regex_error::regex_error(const std::string& s, regex_constants::error_type err, std::ptrdiff_t pos) 
-   : std::runtime_error(s)
-   , m_error_code(err)
-   , m_position(pos) 
-{
-}
-
-regex_error::regex_error(regex_constants::error_type err) 
-   : std::runtime_error(::boost::BOOST_REGEX_DETAIL_NS::get_default_error_string(err))
-   , m_error_code(err)
-   , m_position(0) 
-{
-}
-
-regex_error::~regex_error() BOOST_NOEXCEPT_OR_NOTHROW
-{
-}
-
-void regex_error::raise()const
-{
-#ifndef BOOST_NO_EXCEPTIONS
-   ::boost::throw_exception(*this);
-#endif
-}
-
-
-
-namespace BOOST_REGEX_DETAIL_NS{
-
-BOOST_REGEX_DECL void BOOST_REGEX_CALL raise_runtime_error(const std::runtime_error& ex)
-{
-   ::boost::throw_exception(ex);
-}
-//
-// error checking API:
-//
-BOOST_REGEX_DECL void BOOST_REGEX_CALL verify_options(boost::regex::flag_type /*ef*/, match_flag_type mf)
-{
-#ifndef BOOST_REGEX_V3
-   //
-   // can't mix match_extra with POSIX matching rules:
-   //
-   if((mf & match_extra) && (mf & match_posix))
-   {
-      std::logic_error msg("Usage Error: Can't mix regular expression captures with POSIX matching rules");
-      throw_exception(msg);
-   }
-#endif
-}
-
-#ifdef BOOST_REGEX_HAS_MS_STACK_GUARD
+namespace boost {
+namespace BOOST_REGEX_DETAIL_NS {
 
 static void execute_eror()
 {
@@ -175,52 +106,10 @@ BOOST_REGEX_DECL void BOOST_REGEX_CALL reset_stack_guard_page()
    }
 #endif
 }
-#endif
-
-#if defined(BOOST_REGEX_NON_RECURSIVE) && !defined(BOOST_REGEX_V3)
-
-#if BOOST_REGEX_MAX_CACHE_BLOCKS == 0
-
-BOOST_REGEX_DECL void* BOOST_REGEX_CALL get_mem_block()
-{
-   return ::operator new(BOOST_REGEX_BLOCKSIZE);
 }
-
-BOOST_REGEX_DECL void BOOST_REGEX_CALL put_mem_block(void* p)
-{
-   ::operator delete(p);
-}
-
-#else
-
-#if defined(BOOST_REGEX_MEM_BLOCK_CACHE_LOCK_FREE)
-mem_block_cache block_cache = { { {nullptr} } } ;
-#elif defined(BOOST_HAS_THREADS)
-mem_block_cache block_cache = { 0, 0, BOOST_STATIC_MUTEX_INIT, };
-#else
-mem_block_cache block_cache = { 0, 0, };
+} // namspaces
 #endif
 
-BOOST_REGEX_DECL void* BOOST_REGEX_CALL get_mem_block()
-{
-   return block_cache.get();
-}
-
-BOOST_REGEX_DECL void BOOST_REGEX_CALL put_mem_block(void* p)
-{
-   block_cache.put(p);
-}
-
-#endif
-
-#endif
-
-} // namespace BOOST_REGEX_DETAIL_NS
-
-
-
-} // namespace boost
-
 #if defined(BOOST_RE_USE_VCL) && defined(BOOST_REGEX_DYN_LINK)
 
 int WINAPI DllEntryPoint(HINSTANCE , unsigned long , void*)