Empty struct, any runtime cost?

[SimonN via Digitalmars-d-learn]

Hi,

in a release-like build, I'm using the tharsis profiler, which is 
a
frame-based profiler. Zone is a RAII struct that measures how 
long its own
lifetime is.

     with (Zone(my_profiler, "zone name to appear in output")) {
         do_expensive_work();
         do_some_more_work();
     }
     // Zone goes out of scope here

I would like to use this code without modification in a release 
build
without profiling. I would rather not put version statements 
everywhere.
I have only one version statement in a single file that's 
included by
all files doing profiling:

     version (release_with_profiling) {
         public import tharsis.prof;
     }
     else {
         class Profiler { }
         struct Zone { this(Profiler, string) { } }
     }

Using that, the first code sample compiles in the non-profiling 
build,
where Zone is an empty struct.

*   Will the empty struct get optimized away completely by the 
compiler,
     at least if we pass -O -inline? I'd really like that, I have
     profiling code in several inner loops.

*   If not, what other approach could be usable to keep 
boilerplate in
     most source files to a minimum?

-- Simon