Remove workarounds for CMake<3.11

Installation/cmake/modules/CGAL_Boost_iostreams_support.cmake

@@ -1,3 +1,4 @@
+cmake_minimum_required(VERSION 3.11)
 if(Boost_IOSTREAMS_FOUND AND NOT TARGET CGAL::Boost_iostreams_support)
 
   if( WIN32 )
@@ -32,13 +33,7 @@ if(Boost_IOSTREAMS_FOUND AND NOT TARGET CGAL::Boost_iostreams_support)
 
   add_library(CGAL::Boost_iostreams_support INTERFACE IMPORTED)
 
-  if(CMAKE_VERSION VERSION_LESS 3.11)
+  set_target_properties(CGAL::Boost_iostreams_support PROPERTIES
-    set_target_properties(CGAL::Boost_iostreams_support PROPERTIES
+    INTERFACE_COMPILE_DEFINITIONS "CGAL_LINKED_WITH_BOOST_IOSTREAMS")
-      INTERFACE_COMPILE_DEFINITIONS "CGAL_LINKED_WITH_BOOST_IOSTREAMS"
+  target_link_libraries(CGAL::Boost_iostreams_support INTERFACE ${Boost_LIB} ${ZLIB_LIBS})
-      INTERFACE_LINK_LIBRARIES "${Boost_LIB};${ZLIB_LIBS}")
-  else()
-    set_target_properties(CGAL::Boost_iostreams_support PROPERTIES
-      INTERFACE_COMPILE_DEFINITIONS "CGAL_LINKED_WITH_BOOST_IOSTREAMS")
-    target_link_libraries(CGAL::Boost_iostreams_support INTERFACE ${Boost_LIB} ${ZLIB_LIBS})
-  endif()
 endif()

Installation/cmake/modules/CGAL_Common.cmake

@@ -17,13 +17,6 @@ if( NOT CGAL_COMMON_FILE_INCLUDED )
     message( FATAL_ERROR "CMAKE_ROOT environment variable not set. It should point to the directory where CMake is installed.")
   endif()
 
-  # CMAKE_VERSION was introduced in 2.6.3 so we use it to detect the fact
-  if ( CMAKE_VERSION )
-    set( CMAKE_2_6_3_OR_ABOVE TRUE )
-  else()
-    set( CMAKE_2_6_3_OR_ABOVE FALSE )
-  endif()
-
   if ( WIN32 )
     find_program(CMAKE_UNAME uname /bin /usr/bin /usr/local/bin )
     if(CMAKE_UNAME)

Installation/cmake/modules/CGAL_SetupCGALDependencies.cmake

@@ -23,6 +23,7 @@
 #    If set, the `LEDA` library will be searched and used to provide
 #    the exact number types used by CGAL kernels.
 #
+cmake_minimum_required(VERSION 3.11)
 if(CGAL_SetupCGALDependencies_included)
   return()
 endif()
@@ -117,22 +118,12 @@ function(CGAL_setup_CGAL_dependencies target)
   if(MSVC)
     target_compile_options(${target} INTERFACE
       "-D_SCL_SECURE_NO_DEPRECATE;-D_SCL_SECURE_NO_WARNINGS")
-    if(CMAKE_VERSION VERSION_LESS 3.11)
+    target_compile_options(${target} INTERFACE
-      target_compile_options(${target} INTERFACE
+      $<$<COMPILE_LANGUAGE:CXX>:/fp:strict>
-        /fp:strict
+      $<$<COMPILE_LANGUAGE:CXX>:/fp:except->
-        /fp:except-
+      $<$<COMPILE_LANGUAGE:CXX>:/wd4503>  # Suppress warnings C4503 about "decorated name length exceeded"
-        /wd4503  # Suppress warnings C4503 about "decorated name length exceeded"
+      $<$<COMPILE_LANGUAGE:CXX>:/bigobj>  # Use /bigobj by default
-        /bigobj  # Use /bigobj by default
+      )
-        )
-    else()
-      # The MSVC generator supports `$<COMPILE_LANGUAGE: >` since CMake 3.11.
-      target_compile_options(${target} INTERFACE
-        $<$<COMPILE_LANGUAGE:CXX>:/fp:strict>
-        $<$<COMPILE_LANGUAGE:CXX>:/fp:except->
-        $<$<COMPILE_LANGUAGE:CXX>:/wd4503>  # Suppress warnings C4503 about "decorated name length exceeded"
-        $<$<COMPILE_LANGUAGE:CXX>:/bigobj>  # Use /bigobj by default
-        )
-    endif()
   elseif ("${CMAKE_CXX_COMPILER_ID}" MATCHES "AppleClang")
     if (CMAKE_CXX_COMPILER_VERSION VERSION_LESS 11.0.3)
       message(STATUS "Apple Clang version ${CMAKE_CXX_COMPILER_VERSION} compiler detected")
@@ -157,11 +148,7 @@ function(CGAL_setup_CGAL_dependencies target)
     endif()
     if(CMAKE_CXX_COMPILER_VERSION VERSION_GREATER 3)
       message( STATUS "Using gcc version 4 or later. Adding -frounding-math" )
-      if(CMAKE_VERSION VERSION_LESS 3.3)
+      target_compile_options(${target} INTERFACE "$<$<COMPILE_LANGUAGE:CXX>:-frounding-math>")
-        target_compile_options(${target} INTERFACE "-frounding-math")
-      else()
-        target_compile_options(${target} INTERFACE "$<$<COMPILE_LANGUAGE:CXX>:-frounding-math>")
-      endif()
     endif()
     if ( "${GCC_VERSION}" MATCHES "^4.2" )
       message( STATUS "Using gcc version 4.2. Adding -fno-strict-aliasing" )

Installation/cmake/modules/CGAL_SetupLEDA.cmake

@@ -9,7 +9,7 @@
 #    find_package(LEDA)
 #
 # and defines the function :command:`use_CGAL_LEDA_support`.
-
+cmake_minimum_required(VERSION 3.11)
 if(CGAL_SetupLEDA_included)
   return()
 endif()
@@ -39,11 +39,7 @@ function(use_CGAL_LEDA_support target)
   separate_arguments(LIST_LEDA_CXX_FLAGS UNIX_COMMAND "${LEDA_CXX_FLAGS}")
   separate_arguments(LIST_LEDA_DEFINITIONS UNIX_COMMAND "${LEDA_DEFINITIONS} -DCGAL_USE_LEDA")
 
-  if(CMAKE_VERSION VERSION_LESS 3.3)
+  target_compile_options(${target} INTERFACE $<$<COMPILE_LANGUAGE:CXX>:${LIST_LEDA_CXX_FLAGS}>)
-    target_compile_options(${target} INTERFACE ${LIST_LEDA_CXX_FLAGS})
-  else()
-    target_compile_options(${target} INTERFACE $<$<COMPILE_LANGUAGE:CXX>:${LIST_LEDA_CXX_FLAGS}>)
-  endif()
   target_compile_options(${target} INTERFACE ${LIST_LEDA_DEFINITIONS})
 
   target_include_directories(${target} SYSTEM INTERFACE ${LEDA_INCLUDE_DIR})