CMP0012ΒΆ
Warning
The OLD behavior of this policy was removed
in CMake version 4.0.
This policy must be set to NEW by a call to
cmake_minimum_required() or cmake_policy().
if() recognizes numbers and boolean constants.
In CMake versions 2.6.4 and lower the if() command implicitly
dereferenced arguments corresponding to variables, even those named
like numbers or boolean constants, except for 0 and 1. Numbers and
boolean constants such as true, false, yes, no, on,
off, y, n, notfound, ignore (all case insensitive)
were recognized in some cases but not all. For example, the code if(TRUE)
might have evaluated as false.
Numbers such as 2 were recognized only in boolean expressions
like if(NOT 2) (leading to false) but not as a single-argument like
if(2) (also leading to false). Later versions of CMake prefer to
treat numbers and boolean constants literally, so they should not be
used as variable names.
The OLD behavior for this policy is to implicitly dereference
variables named like numbers and boolean constants. The NEW behavior
for this policy is to recognize numbers and boolean constants without
dereferencing variables with such names.
This policy was introduced in CMake version 2.8.0.
Prior to removal in CMake version 4.0, it could be
set by cmake_policy() or cmake_minimum_required().
If it was not set, CMake warned, and used OLD behavior.