diff --git a/Installation/CMakeLists.txt b/Installation/CMakeLists.txt
index 18133ff36fc..18a0c9b3797 100644
--- a/Installation/CMakeLists.txt
+++ b/Installation/CMakeLists.txt
@@ -910,7 +910,7 @@ install(PROGRAMS ${scripts} DESTINATION ${CGAL_INSTALL_BIN_DIR})
 install(DIRECTORY ${CGAL_MODULES_REL_DIR}/                DESTINATION ${CGAL_INSTALL_CMAKE_DIR} )
 install(FILES     ${CGAL_MODULES_REL_DIR}/UseCGAL.cmake   DESTINATION ${CGAL_INSTALL_CMAKE_DIR} )
 
-if ( GMP_IN_CGAL_AUXILIARY OR MPFR_IN_CGAL_AUXILIARY )
+if ( IS_DIRECTORY auxiliary/gmp/include AND IS_DIRECTORY auxiliary/gmp/lib )
   install(DIRECTORY auxiliary/gmp/include/ DESTINATION ${CGAL_INSTALL_INC_DIR} )
   install(DIRECTORY auxiliary/gmp/lib/     DESTINATION ${CGAL_INSTALL_LIB_DIR} )
 endif()
diff --git a/Installation/cmake/modules/CGAL_SetupGMP.cmake b/Installation/cmake/modules/CGAL_SetupGMP.cmake
index 082d926c0ee..1a8c28a3c13 100644
--- a/Installation/cmake/modules/CGAL_SetupGMP.cmake
+++ b/Installation/cmake/modules/CGAL_SetupGMP.cmake
@@ -56,14 +56,14 @@ function(use_CGAL_GMP_support target)
     return()
   endif()
 
-  if(NOT GMP_IN_CGAL_AUXILIARY)
+  if(NOT GMP_INCLUDE_DIR STREQUAL "${CGAL_INSTALLATION_PACKAGE_DIR}/auxiliary/gmp/include")
     target_include_directories(${target} SYSTEM ${keyword} ${GMP_INCLUDE_DIR})
   else()
     target_include_directories(${target} SYSTEM ${keyword}
       $<BUILD_INTERFACE:${GMP_INCLUDE_DIR}>
       $<INSTALL_INTERFACE:include>)
   endif()
-  if(NOT MPFR_IN_CGAL_AUXILIARY)
+  if(NOT MPFR_INCLUDE_DIR STREQUAL "${CGAL_INSTALLATION_PACKAGE_DIR}/auxiliary/gmp/include")
     target_include_directories(${target} SYSTEM ${keyword} ${MPFR_INCLUDE_DIR})
   else()
     target_include_directories(${target} SYSTEM ${keyword}
diff --git a/Installation/cmake/modules/CGAL_enable_end_of_configuration_hook.cmake b/Installation/cmake/modules/CGAL_enable_end_of_configuration_hook.cmake
index 2401063a25f..6f8e423af1d 100644
--- a/Installation/cmake/modules/CGAL_enable_end_of_configuration_hook.cmake
+++ b/Installation/cmake/modules/CGAL_enable_end_of_configuration_hook.cmake
@@ -14,11 +14,47 @@ if(PROPERTY_CGAL_run_at_the_end_of_configuration_INCLUDED)
 endif()
 
 function(CGAL_run_at_the_end_of_configuration variable access value current_list_file stack)
-  if(NOT access STREQUAL "MODIFIED_ACCESS" OR value)
-    # Only do something at the end of the CMake process, when the value of
-    # variable CMAKE_CURRENT_LIST_DIR is changed to the empty string.
+  if(NOT access STREQUAL "MODIFIED_ACCESS")
     return()
   endif()
+  if(CGAL_CHECK_UNUSED_CPP_FILES
+      AND NOT current_list_file STREQUAL "${CMAKE_CURRENT_SOURCE_DIR}/CMakeLists.txt"
+      AND stack STREQUAL "${CMAKE_CURRENT_SOURCE_DIR}/CMakeLists.txt")
+    file(GLOB _cppfiles ${CMAKE_CURRENT_SOURCE_DIR}/*.cpp)
+    get_property(_targets DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY BUILDSYSTEM_TARGETS)
+    if(_targets AND _cppfiles)
+      set(_sources)
+      foreach(_target ${_targets})
+        get_property(_target_type TARGET ${_target} PROPERTY TYPE)
+        if(_target_type STREQUAL INTERFACE_LIBRARY)
+          continue()
+        endif()
+        get_property(_target_sources TARGET ${_target} PROPERTY SOURCES)
+        list(APPEND _sources ${_target_sources})
+      endforeach()
+      if(_sources)
+        list(REMOVE_ITEM _cppfiles ${_sources})
+      endif()
+      if(_cppfiles)
+        set(_warning "In ${CMAKE_CURRENT_SOURCE_DIR}, the following files are unused:")
+        foreach(_cppfile ${_cppfiles})
+          set(_warning "${_warning}
+  ${_cppfile}")
+        endforeach()
+        set(_warning  "${_warning}
+")
+        message(AUTHOR_WARNING "${_warning}")
+      endif()
+    endif()
+  endif()
+
+  if(value)
+    # Only do the following at the end of the CMake process, when the
+    # value of variable CMAKE_CURRENT_LIST_DIR is changed to the empty
+    # string.
+    return()
+  endif()
+
   # Warn when CMAKE_BUILD_TYPE is empty or Debug
   if(DEFINED CMAKE_BUILD_TYPE AND ( NOT CMAKE_BUILD_TYPE OR CMAKE_BUILD_TYPE STREQUAL "Debug") )
     set(keyword WARNING)
diff --git a/Installation/cmake/modules/FindGMP.cmake b/Installation/cmake/modules/FindGMP.cmake
index f3084cc72f7..663203d11c9 100644
--- a/Installation/cmake/modules/FindGMP.cmake
+++ b/Installation/cmake/modules/FindGMP.cmake
@@ -4,7 +4,6 @@
 #  GMP_INCLUDE_DIR       - the GMP include directory
 #  GMP_LIBRARIES_DIR     - directory where the GMP libraries are located
 #  GMP_LIBRARIES         - Link these to use GMP
-#  GMP_IN_CGAL_AUXILIARY - TRUE if the GMP found is the one distributed with CGAL in the auxiliary folder
 
 # TODO: support MacOSX
 
@@ -52,8 +51,3 @@ if( NOT GMP_in_cache )
 endif()
 
 find_package_handle_standard_args(GMP "DEFAULT_MSG" GMP_LIBRARIES GMP_INCLUDE_DIR)
-
-if ( GMP_INCLUDE_DIR STREQUAL "${CGAL_INSTALLATION_PACKAGE_DIR}/auxiliary/gmp/include" )
-  cache_set( GMP_IN_CGAL_AUXILIARY TRUE )
-endif()
-
diff --git a/Installation/cmake/modules/FindMPFR.cmake b/Installation/cmake/modules/FindMPFR.cmake
index cb3c0fc1c73..b21fb1f678e 100644
--- a/Installation/cmake/modules/FindMPFR.cmake
+++ b/Installation/cmake/modules/FindMPFR.cmake
@@ -3,7 +3,6 @@
 # MPFR_INCLUDE_DIR - the MPFR include directory
 # MPFR_LIBRARIES_DIR - Directory where the MPFR libraries are located
 # MPFR_LIBRARIES - the MPFR libraries
-# MPFR_IN_CGAL_AUXILIARY - TRUE if the MPFR found is the one distributed with CGAL in the auxiliary folder
 
 # TODO: support MacOSX
 
@@ -51,7 +50,3 @@ if (NOT MPFR_in_cache)
 endif()
 
 find_package_handle_standard_args(MPFR "DEFAULT_MSG" MPFR_LIBRARIES MPFR_INCLUDE_DIR)
-
-if ( MPFR_INCLUDE_DIR STREQUAL "${CGAL_INSTALLATION_PACKAGE_DIR}/auxiliary/gmp/include" )
-  cache_set( MPFR_IN_CGAL_AUXILIARY TRUE )
-endif()
diff --git a/Installation/src/CGAL_libs_verinfo.rc.in b/Installation/src/CGAL_libs_verinfo.rc.in
index d1f838e8db6..56a65021857 100644
--- a/Installation/src/CGAL_libs_verinfo.rc.in
+++ b/Installation/src/CGAL_libs_verinfo.rc.in
@@ -25,7 +25,7 @@
 #define CGAL_VER_str(s) CGAL_VER_xstr(s)
 
 #define CGAL_VER_VERSION CGAL_VERSION_MAJOR,CGAL_VERSION_MINOR,CGAL_VERSION_PATCH,CGAL_VERSION_BUILD
-#define CGAL_VER_VERSION_STR CGAL_VER_str(CGAL_VERSION)
+#define CGAL_VER_VERSION_STR CGAL_VER_str(CGAL_VERSION_MAJOR) "." CGAL_VER_str(CGAL_VERSION_MINOR) "." CGAL_VER_str(CGAL_VERSION_PATCH) "." CGAL_VER_str(CGAL_VERSION_BUILD)
 #define CGAL_VER_COMPANYNAME_STR "The CGAL Project, https://www.cgal.org/\0"
 #define CGAL_VER_FILEDESCRIPTION_STR "@LIBRARY_NAME@ Library\0"
 #define CGAL_VER_FILEVERSION_STR CGAL_VER_VERSION_STR
diff --git a/Installation/test/Installation/CMakeLists.txt b/Installation/test/Installation/CMakeLists.txt
index 6dd0c4b41c3..c5d6f6c02db 100644
--- a/Installation/test/Installation/CMakeLists.txt
+++ b/Installation/test/Installation/CMakeLists.txt
@@ -79,10 +79,13 @@ if ( CGAL_FOUND )
     endif()
   endif()
 
-  if(WIN32) 
+  if(WIN32 OR CMAKE_SYSTEM_NAME STREQUAL Windows)
+    add_executable(display_dll_version_info display_dll_version_info.cpp)
+    target_link_libraries(display_dll_version_info version)
     add_executable(test_gmp_mpfr_dll test_gmp_mpfr_dll.cpp)
-    target_link_libraries(test_gmp_mpfr_dll Version)
-  endif(WIN32)
+    target_link_libraries(test_gmp_mpfr_dll version)
+    CGAL_add_test(test_gmp_mpfr_dll)
+  endif()
 
   find_package( LEDA QUIET)
   if(LEDA_FOUND)
diff --git a/Installation/test/Installation/display_dll_version_info.cpp b/Installation/test/Installation/display_dll_version_info.cpp
index 985e2ed15af..2ed4da4742c 100644
--- a/Installation/test/Installation/display_dll_version_info.cpp
+++ b/Installation/test/Installation/display_dll_version_info.cpp
@@ -49,7 +49,7 @@ int main(int argc, char** argv) {
   } else {
     std::cerr << "Usage:\n"
               << "  display_dll_version_info /path/to/a.dll\n";
-    return 0;
   }
+  return 0;
 }
 #endif
diff --git a/Polyhedron/demo/Polyhedron/CMakeLists.txt b/Polyhedron/demo/Polyhedron/CMakeLists.txt
index 9090f621866..84fd430f3f4 100644
--- a/Polyhedron/demo/Polyhedron/CMakeLists.txt
+++ b/Polyhedron/demo/Polyhedron/CMakeLists.txt
@@ -148,9 +148,10 @@ if(CGAL_Qt5_FOUND AND Qt5_FOUND AND OPENGL_FOUND )
 
   qt5_add_resources ( CGAL_Qt5_RESOURCE_FILES Polyhedron_3.qrc )
   find_path(CGAL_THREE_HEADERS_PATH
-    NAME CGAL/Three/Scene_item.h
+    NAMES CGAL/Three/Scene_item.h
     HINTS ${CGAL_INCLUDE_DIRS}
     NO_DEFAULT_PATH
+    NO_CMAKE_FIND_ROOT_PATH
     DOC "Path to CGAL/Three/Scene_item.h")
   
   if(CGAL_THREE_HEADERS_PATH)
@@ -165,7 +166,7 @@ if(CGAL_Qt5_FOUND AND Qt5_FOUND AND OPENGL_FOUND )
     qt5_generate_moc( "${CGAL_THREE_HEADERS_PATH}/CGAL/Three/TextRenderer.h"
       "${CMAKE_CURRENT_BINARY_DIR}/TextRenderer_moc.cpp" )
   else()
-    message(FATAL_ERROR "Cannot find <CGAL/Three/Viewer_interface.h>")
+    message(FATAL_ERROR "Cannot find <CGAL/Three/Scene_item.h>")
   endif()
 
   unset(CGAL_THREE_HEADERS_PATH CACHE)
diff --git a/STL_Extension/include/CGAL/Compact_container.h b/STL_Extension/include/CGAL/Compact_container.h
index 2396e370e89..a31df3910b0 100644
--- a/STL_Extension/include/CGAL/Compact_container.h
+++ b/STL_Extension/include/CGAL/Compact_container.h
@@ -28,6 +28,7 @@
 #include <CGAL/Default.h>
 
 #include <cmath>
+#include <cstddef>
 #include <iterator>
 #include <algorithm>
 #include <vector>
@@ -815,7 +816,8 @@ private:
 
   static char * clean_pointer(char * p)
   {
-    return ((p - (char *) NULL) & ~ (std::ptrdiff_t) START_END) + (char *) NULL;
+    return reinterpret_cast<char*>(reinterpret_cast<std::ptrdiff_t>(p) &
+                                   ~ (std::ptrdiff_t) START_END);
   }
 
   // Returns the pointee, cleaned up from the squatted bits.
@@ -828,7 +830,8 @@ private:
   static Type type(const_pointer ptr)
   {
     char * p = (char *) Traits::pointer(*ptr);
-    return (Type) (p - clean_pointer(p));
+    return (Type) (reinterpret_cast<std::ptrdiff_t>(p) -
+                   reinterpret_cast<std::ptrdiff_t>(clean_pointer(p)));
   }
 
   // Sets the pointer part and the type of the pointee.
@@ -837,7 +840,8 @@ private:
     // This out of range compare is always true and causes lots of
     // unnecessary warnings.
     // CGAL_precondition(0 <= t && t < 4);
-    Traits::pointer(*ptr) = (void *) ((clean_pointer((char *) p)) + (int) t);
+    Traits::pointer(*ptr) = reinterpret_cast<void *>
+      (reinterpret_cast<std::ptrdiff_t>(clean_pointer((char *) p)) + (int) t);
   }
 
 public:
diff --git a/STL_Extension/include/CGAL/Iterator_range.h b/STL_Extension/include/CGAL/Iterator_range.h
index 1d906900968..39c79bd1d3f 100644
--- a/STL_Extension/include/CGAL/Iterator_range.h
+++ b/STL_Extension/include/CGAL/Iterator_range.h
@@ -77,6 +77,18 @@ namespace CGAL {
   {
     return begin()==end();
   }
+#ifndef CGAL_CFG_NO_CPP0X_TUPLE
+
+  operator std::tuple<I&, I&>()
+  {
+    return std::tuple<I&, I&>{this->first, this->second};
+  }
+
+  operator std::tuple<const I&, const I&>() const 
+  {
+    return std::tuple<const I&, const I&>{this->first, this->second};
+  }
+#endif
 
 };