diff options
| -rw-r--r-- | Help/policy/CMP0054.rst | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/Help/policy/CMP0054.rst b/Help/policy/CMP0054.rst index 39f0c40..3754fda 100644 --- a/Help/policy/CMP0054.rst +++ b/Help/policy/CMP0054.rst @@ -16,29 +16,33 @@ Given the following partial example: :: - set(MONKEY 1) - set(ANIMAL MONKEY) + set(A E) + set(E "") - if("${ANIMAL}" STREQUAL "MONKEY") + if("${A}" STREQUAL "") + message("Result is TRUE before CMake 3.1 or when CMP0054 is OLD") + else() + message("Result is FALSE in CMake 3.1 and above if CMP0054 is NEW") + endif() After explicit expansion of variables this gives: :: - if("MONKEY" STREQUAL "MONKEY") + if("E" STREQUAL "") With the policy set to ``OLD`` implicit expansion reduces this semantically to: :: - if("1" STREQUAL "1") + if("" STREQUAL "") With the policy set to ``NEW`` the quoted arguments will not be further dereferenced: :: - if("MONKEY" STREQUAL "MONKEY") + if("E" STREQUAL "") This policy was introduced in CMake version 3.1. CMake version |release| warns when the policy is not set and uses |