Oh microbenchmarks.<p>All of this is going to be optimized away by a sufficiently smart compiler or a compiler you tell you want to spend lots of time optimizing.<p>In general: don&#x27;t write microbenchmarks where the results can be easily statically evaluated by the compiler, unless you are testing whether the compiler can statically evaluate it (this is a reasonable thing to want to know of course, but it&#x27;s not a test of the language).<p>There are also languages which will pretty much not bother to do a lot of the  the actual work, like haskell.<p>(Note: In this case, the the C++ compiler being used actually knows all the recurrences involved, but decides it&#x27;s too expensive to statically calculate the final result of sum.  GCC would do the same.)