Doesn't F# still perform worse than C# in various scenarios? IIRC the functional glue adds some overhead and F# uses classes instead of structs in some cases.
I have not found that to be the case. Yes, sometimes certain idiomatic things in F# might be slower, but in that case, just write them like you would in C# and you'll get the same performance. So, at worst, you end up with the same code, with more concise syntax.
There are a few exceptions, but in general, F# can emit anything C# can.
In fact, with F#'s "inline" ability, you have more flexibility than you do in C# - the CLR does vastly better when handed a big IL function, versus expecting it to get inlining right. The F# compiler does more advanced optimizations, too.
Just straight up writing F# as if it was C# gives you similar runtime results, with sometimes shockingly less code due to how much more concise the syntax is. C# and F# interop is also pretty painless if you do run into something that simply can't be done performantly enough in F#.
There are some cases where the F# compiler emits slightly less-efficient code than the C# compiler. However, in my experience I've found that I'm able to implement algorithms much more efficiently in F# than C#, which more than makes up for any compiler inefficiencies.
