3.8.2/share/cmake-3.8/Modules/BasicConfigVersion-AnyNewerVersion.cmake.in

# This is a basic version file for the Config-mode of find_package().
# It is used by write_basic_package_version_file() as input file for configure_file()
# to create a version-file which can be installed along a config.cmake file.
#
# The created file sets PACKAGE_VERSION_EXACT if the current version string and
# the requested version string are exactly the same and it sets
# PACKAGE_VERSION_COMPATIBLE if the current version is >= requested version.
# The variable CVF_VERSION must be set before calling configure_file().

set(PACKAGE_VERSION "@CVF_VERSION@")

if(PACKAGE_VERSION VERSION_LESS PACKAGE_FIND_VERSION)
  set(PACKAGE_VERSION_COMPATIBLE FALSE)
else()
  set(PACKAGE_VERSION_COMPATIBLE TRUE)
  if(PACKAGE_FIND_VERSION STREQUAL PACKAGE_VERSION)
    set(PACKAGE_VERSION_EXACT TRUE)
  endif()
endif()

# if the installed or the using project don't have CMAKE_SIZEOF_VOID_P set, ignore it:
if("${CMAKE_SIZEOF_VOID_P}" STREQUAL "" OR "@CMAKE_SIZEOF_VOID_P@" STREQUAL "")
   return()
endif()

# check that the installed version has the same 32/64bit-ness as the one which is currently searching:
if(NOT CMAKE_SIZEOF_VOID_P STREQUAL "@CMAKE_SIZEOF_VOID_P@")
   math(EXPR installedBits "@CMAKE_SIZEOF_VOID_P@ * 8")
   set(PACKAGE_VERSION "${PACKAGE_VERSION} (${installedBits}bit)")
   set(PACKAGE_VERSION_UNSUITABLE TRUE)
endif()