[CMake] Problem with CHECK_INCLUDE_FILE macro

[Brad King]

Philippe Poilbarbe wrote:
> I have reread the IF description but nothing of this kind appears to me 
> (I use the book Mastering CMake), there is only a description of DEFINED 
> (but perhaps my english is not good enough :)).

From:

   cmake --help-command IF

I get (among other information):

  ...
    IF(variable MATCHES regex)
    IF(string MATCHES regex)
  True if the given string or variable's value matches
  the given regular expression.
  ...

Note the first syntax.

-Brad