Use regex from C++11 instead of boost/tr1's version (the latter is gone as of boost 1.65).
Patch: https://svnweb.freebsd.org/ports/head/devel/libcutl/files/patch-cutl_re_re.cxx?view=markup&pathrev=445764
Bug: https://bugs.gentoo.org/show_bug.cgi?id=630016

--- a/cutl/re/re.cxx
+++ b/cutl/re/re.cxx
@@ -9,7 +9,7 @@
 #ifndef LIBCUTL_EXTERNAL_BOOST
 #  include <cutl/details/boost/tr1/regex.hpp>
 #else
-#  include <boost/tr1/regex.hpp>
+#  include <regex>
 #endif
 
 using namespace std;
@@ -40,17 +40,17 @@
     struct basic_regex<C>::impl
     {
       typedef basic_string<C> string_type;
-      typedef tr1::basic_regex<C> regex_type;
+      typedef std::basic_regex<C> regex_type;
       typedef typename regex_type::flag_type flag_type;
 
       impl () {}
       impl (regex_type const& r): r (r) {}
       impl (string_type const& s, bool icase)
       {
-        flag_type f (tr1::regex_constants::ECMAScript);
+        flag_type f (std::regex_constants::ECMAScript);
 
         if (icase)
-          f |= tr1::regex_constants::icase;
+          f |= std::regex_constants::icase;
 
         r.assign (s, f);
       }
@@ -118,15 +118,15 @@
           impl_ = s == 0 ? new impl : new impl (*s, icase);
         else
         {
-          impl::flag_type f (tr1::regex_constants::ECMAScript);
+          impl::flag_type f (std::regex_constants::ECMAScript);
 
           if (icase)
-            f |= tr1::regex_constants::icase;
+            f |= std::regex_constants::icase;
 
           impl_->r.assign (*s, f);
         }
       }
-      catch (tr1::regex_error const& e)
+      catch (std::regex_error const& e)
       {
         throw basic_format<char> (s == 0 ? "" : *s, e.what ());
       }
@@ -146,15 +146,15 @@
           impl_ = s == 0 ? new impl : new impl (*s, icase);
         else
         {
-          impl::flag_type f (tr1::regex_constants::ECMAScript);
+          impl::flag_type f (std::regex_constants::ECMAScript);
 
           if (icase)
-            f |= tr1::regex_constants::icase;
+            f |= std::regex_constants::icase;
 
           impl_->r.assign (*s, f);
         }
       }
-      catch (tr1::regex_error const& e)
+      catch (std::regex_error const& e)
       {
         throw basic_format<wchar_t> (s == 0 ? L"" : *s, e.what ());
       }
@@ -166,28 +166,28 @@
     bool basic_regex<char>::
     match (string_type const& s) const
     {
-      return tr1::regex_match (s, impl_->r);
+      return std::regex_match (s, impl_->r);
     }
 
     template <>
     bool basic_regex<wchar_t>::
     match (string_type const& s) const
     {
-      return tr1::regex_match (s, impl_->r);
+      return std::regex_match (s, impl_->r);
     }
 
     template <>
     bool basic_regex<char>::
     search (string_type const& s) const
     {
-      return tr1::regex_search (s, impl_->r);
+      return std::regex_search (s, impl_->r);
     }
 
     template <>
     bool basic_regex<wchar_t>::
     search (string_type const& s) const
     {
-      return tr1::regex_search (s, impl_->r);
+      return std::regex_search (s, impl_->r);
     }
 
     template <>
@@ -196,13 +196,13 @@
              string_type const& sub,
              bool first_only) const
     {
-      tr1::regex_constants::match_flag_type f (
-        tr1::regex_constants::format_default);
+      std::regex_constants::match_flag_type f (
+        std::regex_constants::format_default);
 
       if (first_only)
-        f |= tr1::regex_constants::format_first_only;
+        f |= std::regex_constants::format_first_only;
 
-      return tr1::regex_replace (s, impl_->r, sub, f);
+      return std::regex_replace (s, impl_->r, sub, f);
     }
 
     template <>
@@ -211,13 +211,13 @@
              string_type const& sub,
              bool first_only) const
     {
-      tr1::regex_constants::match_flag_type f (
-        tr1::regex_constants::format_default);
+      std::regex_constants::match_flag_type f (
+        std::regex_constants::format_default);
 
       if (first_only)
-        f |= tr1::regex_constants::format_first_only;
+        f |= std::regex_constants::format_first_only;
 
-      return tr1::regex_replace (s, impl_->r, sub, f);
+      return std::regex_replace (s, impl_->r, sub, f);
     }
   }
 }
--- a/m4/libboost.m4
+++ b/m4/libboost.m4
@@ -129,13 +129,13 @@
 AC_DEFUN([LIBBOOST_REGEX], [
 LIBBOOST_LIB([regex],[
 AC_LANG_SOURCE([
-#include <boost/tr1/regex.hpp>
+#include <regex>
 
 int
 main ()
 {
-  std::tr1::regex r ("te.t", std::tr1::regex_constants::ECMAScript);
-  return std::tr1::regex_match ("test", r) ? 0 : 1;
+  std::regex r ("te.t", std::regex_constants::ECMAScript);
+  return std::regex_match ("test", r) ? 0 : 1;
 }
 ])],
 [$1],