[Cmake] Capture regular expressions

[Brad King]

Filipe Sousa wrote:
> I wrote my own FindQt.cmake so that I could find the right qt lib on Windows. 
> I need to extract the version from global.h. I managed that using two STRING 
> command, but I would like to capture version around parentheses with regular 
> expressions using only one STRING command. Is this possible with cmake?

What do you mean by "version around parentheses"?  Code like this is 
supported:

STRING(REGEX REPLACE "#define[\\t\\ ]+QT_VERSION_STR[\\t\\ 
]+\"([0-9]+\\.[0-9]+\\.[0-9]+)\"" "\\1" qt_version "${VERSION_STR}")

Note the "\\1" in the replace expression.  The two backslashes make it 
through argument processing as a single backslash, and then the "\1" is 
replaced by the part of the string matched inside the parentheses.

-Brad