What Is Type-Level Programming?

Post by sophacles » Wed, May 03, 2023, 4:37 PM UTC

codr7 wrote: post #73

sophacles wrote: post #61

Earlier quoted context omitted.

> Yeah, and it's trivial in C++, what's your point? I see lots of assertions of that fact, but no examples. Care to link some actual code? > Why the hell would you want to change the direction of a pin anyway? Just declare it as Pin or Pin . i2c uses the same pin for sending and receiving and changes the mode of the pin for the purposes of communication with peripherals.

Ok, but then the pin is always both Input/Ouput, so still static; and the example is still as contrived as ever.

Post by gpderetta » Wed, May 03, 2023, 4:55 PM UTC

JonChesterfield wrote: post #82

gpderetta wrote: post #79

I do not believe that the rust solution can be exactly encoded in C++ as the C++ type system itself can't statically guarantee linear typing. You have to use move semantics with a runtime guard... ... except that it might be possible to also "shift left" in C++, by running the pin-using code a compile-time (possibly instantiating it on mock objects) and validate the "runtime guard". This is a rough example https://gc…

Can rust do linear types? I thought it was limited to affine by the exception machinery

Post by shakow » Wed, May 03, 2023, 6:16 PM UTC

pjmlp wrote: post #75

shakow wrote: post #74

Earlier quoted context omitted.

> C like code was presented as C++ Blame Arduino for their stdlib. > was presented as something not available in C++ You are putting things in the author's mouth, they never said that; only that it was not available in Arduino's stdlib.

What about blame the author for their lack of C++ skills while selling Rust, and pretending otherwise?

Post by codr7 » Wed, May 03, 2023, 7:52 PM UTC

pjmlp wrote: post #28

codr7 wrote: post #8

Correct me if I'm wrong, but I see nothing in the Rust example that couldn't just as well be implemented in C++. A comparison to C would have made more sense.

Yeah, many posts from Rust Evangelism Strike Force fail to gain appreciation from the target audience, when they clearly show a lack of understanding of C++ capabilities.

Post by UncleMeat » Wed, May 03, 2023, 9:37 PM UTC

atoav wrote: post #6

FpUser wrote: post #4

>"This looks fine, but what happens if you do not get the pin mode right, for any of many possible reasons?" This is such a contrived and pathetic example. None of it has anything to do with C++ or Rust. It was a decision of whomever wrote pin access libraries. In either of the languages mentioned there is absolutely no problem creating an interface that would return particular pin in "right" state ready to be operat…

But a strongly typed language allows you to check for that error in compile time . As someone who programs embedded I can assure you that you constantly run into that type of error and I could really live without it. So if people could also do that in C/C++ they are apparently not doing it.