> The latter example, sounds like something trivially done by the compiler.

Taken by itself? Absolutely. In the middle of 50-deep templatized call stack? Maybe not. Compilers have their limitations (memory, runtime, other cost budgeting algorithms), and the more complex the code, the hard the optimizer has to work. But, yeah. Most of the gains from branchless code is going to come from this like numerical tools, vectorization and loop unrolling, things of that nature. It was an admittedly contrived example.