Remove Boost.Regex dependency

Travis Xenial container has Boost 1.58.0 built with GCC5 against
the CXX11 ABI. However, there is a bug that affects the Regex library.
Some symbols are missing [abi:cxx11] tags which causes linking to
fail if not also building OSRM with GCC5.
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=823978

Given there is only one use of the Regex libary, use this opportunity
to replace it with std::regex and avoid the linking issue entirely.

CMakeLists.txt

@@ -135,7 +135,7 @@ include_directories(BEFORE ${CMAKE_CURRENT_SOURCE_DIR}/include/)
 include_directories(SYSTEM ${CMAKE_CURRENT_SOURCE_DIR}/third_party/sol2/)
 include_directories(SYSTEM ${CMAKE_CURRENT_SOURCE_DIR}/third_party/variant/include)
 
-set(BOOST_COMPONENTS date_time chrono filesystem iostreams program_options regex system thread unit_test_framework)
+set(BOOST_COMPONENTS date_time chrono filesystem iostreams program_options system thread unit_test_framework)
 
 configure_file(
   ${CMAKE_CURRENT_SOURCE_DIR}/include/util/version.hpp.in
@@ -467,8 +467,6 @@ if(ENABLE_MASON)
   set(Boost_IOSTREAMS_LIBRARY ${MASON_PACKAGE_boost_libiostreams_STATIC_LIBS})
   mason_use(boost_libprogram_options VERSION ${MASON_BOOST_VERSION})
   set(Boost_PROGRAM_OPTIONS_LIBRARY ${MASON_PACKAGE_boost_libprogram_options_STATIC_LIBS})
-  mason_use(boost_libregex VERSION ${MASON_BOOST_VERSION})
-  set(Boost_REGEX_LIBRARY ${MASON_PACKAGE_boost_libregex_STATIC_LIBS})
   mason_use(boost_libtest VERSION ${MASON_BOOST_VERSION})
   set(Boost_UNIT_TEST_FRAMEWORK_LIBRARY ${MASON_PACKAGE_boost_libtest_STATIC_LIBS})
   mason_use(boost_libdate_time VERSION ${MASON_BOOST_VERSION})
@@ -862,4 +860,4 @@ if (ENABLE_NODE_BINDINGS)
   endforeach()
   add_library(check-headers STATIC EXCLUDE_FROM_ALL ${sources})
   set_target_properties(check-headers PROPERTIES ARCHIVE_OUTPUT_DIRECTORY ${check_headers_dir})
-endif()
+endif()

src/extractor/maneuver_override_relation_parser.cpp

@@ -1,14 +1,8 @@
 #include "extractor/maneuver_override_relation_parser.hpp"
 #include "extractor/maneuver_override.hpp"
 
-#include "util/log.hpp"
-
-#include <boost/algorithm/string.hpp>
-#include <boost/algorithm/string/predicate.hpp>
-#include <boost/algorithm/string/regex.hpp>
 #include <boost/optional/optional.hpp>
 #include <boost/ref.hpp>
-#include <boost/regex.hpp>
 
 #include <osmium/osm.hpp>
 #include <osmium/tags/filter.hpp>

src/extractor/restriction_parser.cpp

@@ -4,18 +4,14 @@
 #include "util/conditional_restrictions.hpp"
 #include "util/log.hpp"
 
-#include <boost/algorithm/string.hpp>
 #include <boost/algorithm/string/predicate.hpp>
-#include <boost/algorithm/string/regex.hpp>
 #include <boost/optional/optional.hpp>
 #include <boost/ref.hpp>
-#include <boost/regex.hpp>
 
 #include <osmium/osm.hpp>
 #include <osmium/tags/regex_filter.hpp>
 
 #include <algorithm>
-#include <iterator>
 
 namespace osrm
 {
@@ -246,11 +242,12 @@ bool RestrictionParser::ShouldIgnoreRestriction(const std::string &except_tag_st
 
     // Be warned, this is quadratic work here, but we assume that
     // only a few exceptions are actually defined.
-    std::vector<std::string> exceptions;
-    boost::algorithm::split_regex(exceptions, except_tag_string, boost::regex("[;][ ]*"));
+    const std::regex delimiter_re("[;][ ]*");
+    std::sregex_token_iterator except_tags_begin(except_tag_string.begin(), except_tag_string.end(), delimiter_re, -1);
+    std::sregex_token_iterator except_tags_end;
 
     return std::any_of(
-        std::begin(exceptions), std::end(exceptions), [&](const std::string &current_string) {
+        except_tags_begin, except_tags_end, [&](const std::string &current_string) {
             return std::end(restrictions) !=
                    std::find(std::begin(restrictions), std::end(restrictions), current_string);
         });