--- boost_1_38_0/libs/CMakeLists.txt	2009-01-24 18:57:20.000000000 +0000
+++ boost_1_38_0.patched/libs/CMakeLists.txt	2009-04-01 17:44:35.000000000 +0100
@@ -35,6 +35,51 @@
 set(CPACK_INSTALL_CMAKE_COMPONENTS_ALL)
 list(SORT BOOST_SUBPROJECT_DIRS)
 topological_sort(BOOST_SUBPROJECT_DIRS BOOST_ _DEPENDS)
+
+# Make a bunch of options like ENABLE_upcase(lib) in the cache.  Check
+# if they've been disabled and add the lib to the PRUNE_LIST if they 
+# have.  Make a reverse dependancy table while we're at it.
+set(PRUNE_LIST)
+foreach (proj ${BOOST_SUBPROJECT_DIRS}) 
+  string(TOUPPER ${proj} proj_caps)
+  set(option_var ENABLE_${proj_caps})
+  option(${option_var} "Build the boost.${proj} library; if no then reverse deps are disabled." YES)
+
+  set(dep_list_var "BOOST_${proj_caps}_DEPENDS")
+  foreach (dep ${${dep_list_var}}) 
+    string(TOUPPER ${dep} dep_caps)
+    list(APPEND "BOOST_${dep_caps}_REVDEPENDS" ${proj})
+  endforeach()
+
+  if (NOT ${option_var})
+    message(STATUS "Disabling ${proj} because ${option_var} is off.")
+    set(mark_${dep}_removed TRUE)
+    list(APPEND PRUNE_LIST ${proj})
+  endif()
+endforeach()
+
+# Loop a stack of things to remove.  Take them from BOOST_SUBPROJECT_DIRS.
+# mark_$proj_is our visited flag.
+while(PRUNE_LIST) 
+  list(GET PRUNE_LIST 0 proj)
+  set(mark_${proj}_removed TRUE)
+  list(REMOVE_AT PRUNE_LIST 0)
+  list(REMOVE_ITEM BOOST_SUBPROJECT_DIRS ${proj})
+
+  string(TOUPPER ${proj} proj_caps)
+  # message(STATUS "Disable lib ${proj}")
+  set(revdep_var "BOOST_${proj_caps}_REVDEPENDS")
+  foreach(dep ${${revdep_var}}) 
+    # Don't recurse uselessly.
+    if (NOT mark_${dep}_removed)
+      message(STATUS "Disable ${dep} because it depends on ${proj}")
+      list(INSERT PRUNE_LIST 0 ${dep})
+    endif()
+  endforeach()
+
+  set(${revdep_var})
+endwhile()
+
 add_subdirectories(" + " ${BOOST_SUBPROJECT_DIRS})
 
 # Write out a GraphViz file containing inter-library dependencies.