It’s a still frame from Star Trek The Next Generation, episode The Game

The plot is a wearable device that is an AR “glasses” game that as you play the game it “makes you feel good” gets used to take over the Enterprise so terrorists can hijack it.

At the time I imagine it was intended to be part of anti-drug campaigns with the AR and companies curating what you see to distract from reality angle/sentiment being more relevant today

As someone who is in the aerospace industry and has dealt with safety critical code with NASA oversight, it’s a little disingenuous to pin NASA’s coding standards entirely on attempting to make things memory safe. It’s part of it, yeah, but it’s a very small part. There are a ton of other things that NASA is trying to protect for.

Plus, Rust doesn’t solve the underlying problem that NASA is looking to prevent in banning the C++ standard library. Part of it is DO-178 compliance (or lack thereof) the other part is that dynamic memory has the potential to cause all sorts of problems on resource constrained embedded systems. Statically analyzing dynamic memory usage is virtually impossible, testing for it gets cost prohibitive real quick, it’s just easier to blanket statement ban the STL.

Also, writing memory safe code honestly isn’t that hard. It just requires a different approach to problem solving, that just like any other design pattern, once you learn and get used to it, is easy.

I think part of the “what do I do with this” factor for the iPad was that Apple (and other companies still to this day) were so hell bent on making everything smaller and more compact that releasing a larger product was marketing whiplash. Not to mention that smartphones were being pitched as this “do everything device” so why would you need anything else?

After you get over that marketing sugarcoating, it becomes pretty obvious what you’d use an iPad for. Internet and media consumption at a larger scale than your phone, easier on your eyes than a phone, but retains at least some of the lightweight smaller form factor that separates it from a regular laptop. Sure you didn’t have the stick it in your pocket advantage of a phone or the full keyboard and computational power of a laptop, but there was this in-between that for a modest fee, you could have the conveniences if you can live with/ignore the sacrifices.

I don’t think the MacBook Airs launch is a good comparison.

Sure there was an early adopter tax on being one of the first “thin and light” laptops, but people already know what you can use a MacBook for, there was already a large value proposition in having a MacBook, the extra cost was entirely being more portable than it’s full size counterparts. Everything you can do on a Mac, just way easier to take on the go.

I’ve read a few reviews on it, watched MKBHD’s initial review, and outside of a few demo apps they point to the vision pro having no real point to it. Which if true, then it falls in line with existing VR headsets that are a fraction of it’s cost and in a niche market, being three times the cost of your competitors is not a good position to be

In pure C things are a bit different from what you describe.

Declaration has (annoyingly) multiple definitions depending on the context. The most basic one is when you are creating an instance of a variable, you are telling the compiler that you want a variable with symbol name X, data type Y, and qualifiers A,B and C. During compilation the compiler will read that and start reserving memory for the linker to assign later. These statements are always in the form of “qualifiers data_type symbol;”

Function declaration is a bit different, here you’re telling the compiler “hey you’re going to see this function show up later. Here are the types for arguments and return. I pinky swear promise you’ll get a definition somewhere else”. You can compile without the definition but the linker will get real unhappy if you don’t have the definition when it’s trying to run. Here you’re looking at a statement of “qualifiers return_data_type symbol(arg_1_data_type arg_1_symbol,…);” Technically in function declarations you don’t need argument symbols, just the types, but it’s better to just have them for readability.

Structs are different still. Here you’re telling the compiler that you’re going to have this struct definition somewhere else in the same translation unit, but the data type symbol will show up before the definition. So whenever the compiler sees that data type show up in a variable instance declaration it won’t reserve space right away but it has to have the struct definition before compilation ends. This is pretty straightforward syntax wise, “struct struct_name;” (Typedefs throw a syntax wrench into this that I won’t get into, it’s functionally the same though)

One more thing you can do with variables during declaration is to “extern” them. This is more similar to function declaration, where you’re telling the compiler “hey you’re gonna see this symbol pop up, here’s how you use it, but it actually lives somewhere else k thx bye”. I personally don’t like calling this declaration since it behaves differently than normal declaration. This is the same as a normal variable declaration syntax with “extern” tossed in the front of the qualifiers.

Definitions have two types: Function definitions contain the actual code that gets translated into instructions, Enum, struct, typedef definitions all describe memory requirements when they get used.

Structs and enums will have syntax like “struct struct_name {blah,blah,blah};”, typedefs are just “typedef new_name old_name;”, and function definition “qualifiers return_data_type symbol(arg_1_data_type arg_1_symbol,…) {Blah,blah,blah}” (note that function definitions don’t need a ; at the end and here you do need argument symbols)

Lastly, when you create a variable instance, if you say that you want that symbol to have value X all in one statement, by the standard that’s initialization. So “int foo = 5;” is declaration and initialization. Structs and arrays have special initialization syntax, “struct foo bar = {5, 6, 7};” where the numbers you write out in the list gets applied in order of the element names in the struct definition. You can also use named initialization for structs where it would look like “struct foo bar = {. element_one = 5, .e_two = 6, .e_three = 7};” This style syntax is only available for initialization, you cannot use that syntax for any other assignment. In other words you can’t change elements in bulk, you have to do it one at a time.

C lets you get real wild and combine struct definition, struct instance declaration and initialization all into one! Though if I was your code reviewer I’d reject that for readability.

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