CMake: Small cleanup: Use OPTION(...) instead of SET(BOOL ...)

git-svn-id: https://svn.dealii.org/trunk@29754 0785d39b-7218-0410-832d-ea1e28bc413d

diff --git a/deal.II/cmake/setup_cached_variables.cmake b/deal.II/cmake/setup_cached_variables.cmake
index 7859e1f4a5abf4278f2e44d26791656b45fa96b9..e38c00f14b93ded7b7a99f9fb4af460ceccc03f4 100644 (file)
--- a/deal.II/cmake/setup_cached_variables.cmake
+++ b/deal.II/cmake/setup_cached_variables.cmake
@@ -238,20 +238,16 @@ FOREACH(_flag ${DEAL_II_USED_FLAGS})
 ENDFOREACH()
 
 
-# 
+#
 # Define the variable that defines whether we should use 32- or 64-bit
 # global DoF indices.
 #
-SET(DEAL_II_WITH_64BIT_INDICES "${DEAL_II_WITH_64BIT_INDICES}" CACHE BOOL
-    "If set to ON, then use 64-bit data types to represent global degree of freedom indices. The default is to OFF. You only want to set this to ON if you will solve problems with more than 2^31 (approximately 2 billion) unknowns. If set to ON, you also need to ensure that both Trilinos and/or PETSc support 64-bit indices."
-   )
-
+OPTION(DEAL_II_WITH_64BIT_INDICES
+  "If set to ON, then use 64-bit data types to represent global degree of freedom indices. The default is to OFF. You only want to set this to ON if you will solve problems with more than 2^31 (approximately 2 billion) unknowns. If set to ON, you also need to ensure that both Trilinos and/or PETSc support 64-bit indices."
+  OFF
+  )
 MARK_AS_ADVANCED(DEAL_II_WITH_64BIT_INDICES)
 
-SET_IF_EMPTY(DEAL_II_WITH_64BIT_INDICES "OFF")
-
-
-
 
 #
 # Finally, read in CFLAGS, CXXFLAGS and LDFLAGS from environment and