You do all those things with C++ (or, for fpga, asic, etc., without). There is exactly zero benefit to dropping to C first.

And, nobody suggested anybody actually laughs at C developers. We just don't see them.

> You do all those things with C++ (or, for fpga, asic, etc., without). There is exactly zero benefit to dropping to C first.

That's my point. The performance tuning is generally not between C++ or C hence why you cannot extrapolate your experiences to the rest of the finance industry.

>And, nobody suggested anybody actually laughs at C developers.

You said, "In the finance world, you would be laughed out of the room for proposing C for a performance-critical task."

Then in discussing the nature of the laughter you said "The laughter would not be about measurable performance; you might well be able to get C code to go as fast. The laughter would be over your apparent fear of the C++ compiler, and the suggestion to spend their money on a predictably inferior, more expensive, less maintainable solution."

We have a case in English, as in all languages in its cohort, for discussion of counterfactuals, signaled by "would". If there were anyone proposing C for performance-critical code, they would be laughed at. Happily, none are.