Empty declarations are cruft; they (may) compile, but they violate the language standards, don't contribute anything of value, and clutter up the program. Like cobwebs, they should be swept away.
== Noncompliant Code Example
----
int; // Noncompliant
== See
* ISO/IEC 9899:2011, 6.7p2
* ISO/IEC 14882:2011, 7p3.
* https://wiki.sei.cmu.edu/confluence/x/5dUxBQ[CERT, MSC12-C.] - Detect and remove code that has no effect or is never executed
