title: How to split strings across multiple lines in CMake?
body: <p>I usually have a policy in my project, to never create lines in text files that exceed a line length of 80, so they are easily editable in all kinds of editors (you know the deal). But with CMake I get the problem that I do not know how to split a simple string into multiple lines to avoid one huge line. Consider this basic code:</p>
  <pre><code>set(MYPROJ_VERSION_MAJOR &quot;1&quot;)
  set(MYPROJ_VERSION_MINOR &quot;0&quot;)
  set(MYPROJ_VERSION_PATCH &quot;0&quot;)
  set(MYPROJ_VERSION_EXTRA &quot;rc1&quot;)
  set(MYPROJ_VERSION &quot;${VERSION_MAJOR}.${VERSION_MINOR}.${VERSION_PATCH}-${VERSION_EXTRA}&quot;)
  </code></pre>
  <p>It already exceeds the 80 column limit. So how do I break a line in CMake into multiple lines without getting to verbose (multiple <code>list(APPEND ...)</code> or the like)?</p>