[CMake] Arbitrary order named arguments

[Doug]

There are some cute native functions that let you specify arguments in
random order with named keys preceeding them, eg.

execute_process(COMMAND blah WORKING_DIRECTORY blah2 OUTPUT_FILE x TIMEOUT 2)

===

execute_process(COMMAND blah WORKING_DIRECTORY blah2 TIMEOUT 2 OUTPUT_FILE x)


I'm doing this like this at the moment, but it's clumsy:

function(args NAMED ARGS)
  set(STATE 0)
  foreach(ARG ${ARGS})
    list(FIND NAMED ${ARG} HAS_NAMED_ITEM)
    if(STATE)
      set(${STATE} ${ARG} PARENT_SCOPE)
      set(STATE 0)
    else()
      if(NOT HAS_NAMED_ITEM EQUAL -1)
        set(STATE ${ARG})
      endif()
    endif()
  endforeach()
endfunction()

function(blah)
  set(NAMED_ARGS LD_CONF;C_FLAGS)
  args("${NAMED_ARGS}" "${ARGV}")
  message("C_FLAGS --> ${C_FLAGS}")
  message("LD_CONF --> ${LD_CONF}")
endfunction()

It's particularly annoying when I need a required value (or multiple
ones), like:

function(blah2 REQUIRED)
  list(REMOVE_AT ARGV 0)
  set(NAMED_ARGS LD_CONF;C_FLAGS)
  args("${NAMED_ARGS}" "${ARGV}")
  message("REQUIRED --> ${REQUIRED}")
  message("C_FLAGS --> ${C_FLAGS}")
  message("LD_CONF --> ${LD_CONF}")
endfunction()

blah2("item_required" C_FLAGS "G" LD_CONF "blah")

Anyone suggest a better way?

~
Doug.