[bluGill]

Often the strong type system of C++ means that if take C code and compile it with a C++ compiler it will run faster. Though part of the reason it is faster C++ will allow the compiler to make assumptions that might be false and so there is a (very small IMHO) chance that your code will be wrong after those optimizations. C++ often has better abstractions that if you use will allow C++ to be faster than C can.

If Rust doesn't also compile faster than C because of the better abstractions that should be considered just a sign of compilers needing more work in the optimize and not that Rust can't be faster. Writing optimizers is hard and takes a long time, so I'd expect Rust to be behind.

Note that the above is about real world benchmarks, and is unlikely to amount to 0.03% difference in speed - it takes very special setups to measure these differences, while simple code changes can easially but several hundred percentage differences. Common microbenchmarks generally are not large enough for the type system to make a difference and so often show C as #1 even though in real world problems it isn't.