The Nineteenth Byte

Dannyu NDos

00:45

Is there a modern C++ variant of Steve Oualline's How Not To Program In C++?

Ginger

I didn't know that was a thing that people needed help with :b

Dannyu NDos

Y'know, I need to reinforce my modern C++ skills.

OldSandboxPosts

01:00

Sandbox posts last active a week ago: Compute Pi using pure arithmetic fastest-coderestricted-sourcepythonpi

Dannyu NDos

01:34

I got an idea for an alternate implementation for nullptr: Let the pointer point to itself.

That way, we can save the byte at address zero.

Unrelated String

that would only work for smart-pointer objects that actually have a set address :P

versus raw pointers that you can copy around willy-nilly

Dannyu NDos

That shouldn't be a big problem.

After all, C++ discourages raw pointers.

Unrelated String

and you would very much not want to check if they're self-referential every time you copy one--especially since you might want to use a self-pointer in other circumstances anyways

also it lets you just fault if you try dereferencing it

@DannyuNDos if you're working on a system with little enough memory and memory virtualization and such that saving the byte at address 0 matters, you're going to want to write bare metal :P

Dannyu NDos

Well – nullptr was a million-dollar mistake anyway.

Seggan

Null safe type system go brr

Unrelated String

01:42

^

the existence of null pointers isn't the mistake, it's cramming it into an oo type system

Seggan

Not necessarily

imo kotlin has the perfect null safe type system, but it also has oo

Dannyu NDos

Believe me, I'm writing an interpreter for my new programming language in C++, and its smart pointer inherits a std::map!

It's to check what containers use the pointer.

Freakin' ->*, I've never known I'd have to overload you!

Unrelated String

no that's exactly what i was saying, hoare's billion dollar mistake was making every reference type nullable
which is what kotlin doesn't

Seggan

02:50

Ah

Dannyu NDos

04:06

Anyone remember this numeral system I made?

Unrelated String

vaguely

Dannyu NDos

I actually tried to perform addition, subtraction, and multiplication, and it turns out the worst-case complexity is super-exponential. Dang.

Unrelated String

lmao nice

Dannyu NDos

Guess too much compression led to that.

Unrelated String

what do basic operations on the trees correspond to numerically

Dannyu NDos

04:09

(Whole tree) = 2 ^ (Left tree) * (1 + 2 * (Right tree))

Recursively.

Hard to explain arithmetics.

Unrelated String

ahh

so in a sense it's floating point without any underlying fixed point representation :P

Dannyu NDos

That's a way to put it.

Wait, it's subtraction that sucks; addition and multiplication are still fast.

Unrelated String

ah lol

yeah that makes sense

Dannyu NDos

Wait, addition relies on subtraction. Now it's back to doom. :p

The fault of performing 10000000 - 1. That's where it gets super-exponential.

Unrelated String

:P

New Posts

05:14

0

Q: How to divide the columns in a time series by their first value in R?

I have the code below working. But there must be a better way. file <- "http://s3.amazonaws.com/assets.datacamp.com/production/course_1127/datasets/tmp_file.csv" x <- read.csv(file = file) ts <- xts(x = x, order.by = as.Date(rownames(x), "%m/%d/%Y")) cd=coredata(ts) for (j in 1:length(names(ts))...

matrix r

Sandbox Posts

0

A: Sandbox for Proposed Challenges

Spell date in Japanese Objective Given a date, spell it out in Romanized Japanese. I/O Format The input format is MM/DD. The output format is <month spelling> <day spelling>; note the space. Otherwise flexible. You can freely mix cases in output. Mapping Months Month Spelling January Ichi...

Bbrk24

@NewPosts Why can’t I flag this as off-topic?

okay I think I found it but the flag menu is unnecessarily difficult to navigate on mobile. If I select “belongs on another site” my only option is CGCC meta, I can’t say SO

Unrelated String

that's why we have a "this is a so question" close reason instead :P

Bbrk24

ah I missed that, thanks

lyxal

@UnrelatedString vtc is a 3k privilege though

Unrelated String

05:24

oh

lmao

lyxal

There is no so question flag :p

You're best off mod flagging as needs moving

Bbrk24

I was able to flag it as that despite not having 3k on any individual site

(I do have 3k total, but)

Dannyu NDos

We need more natural-language challenges.

Unrelated String

agreed

they're hard to do right but there's a lot to do there

Dannyu NDos

And I need to post a cops-and-robbers challenge someday.

That said... Has there been any cops-and-robbers that involves a third party?

lyxal

05:33

@Bbrk24 must be a flag that disappears once you can vtc

Bbrk24

@DannyuNDos not strictly a natlang but I’m proud of my lojban consonant cluster TS type answer

1

A: Is it a valid consonant cluster in Lojban?

TypeScript Compiler, 427 bytes type R="l"|"r"|"m"|"n" type U="p"|"t"|"k"|"f"|"c"|"s"|"x" type V="b"|"d"|"g"|"v"|"j"|"z" type S="c"|"s"|"j"|"z" type G<T,W>=T extends W?0:T extends R?1:T extends U?W extends V?0:1:W extends U?0:1 type H<T,W>=T extends"x"?W extends"k"|"c"?0:G<T,W>:T extends"k"|"c"?W ...

Dannyu NDos

If there really was a cops-and-robbers-and-<third party>, how should we call such challenge?

Rock-Paper-Scissors? Terran-Zerg-Protoss? Idk

Bbrk24

How would it work?

Dannyu NDos

@Bbrk24 Rock submissions sabotage Scissors submission, and so on.

That's a crude idea anyway

Unrelated String

ooh

hard to think of an actual challenge for but it's a cool concept

Dannyu NDos

05:41

I'd be better to be posted as a KoTH where submissions choose teams, though.

Dannyu NDos

06:06

*It'd

Dannyu NDos

06:37

tiobe.com/tiobe-index

Guess PLDI would have a hard time.

Neil

@UnrelatedString what type would a self-pointer be?

Unrelated String

in this case i was thinking possibly something like a linked list struct where the next pointer is the first member

so it doesn't exactly point to itself-as-an-object, but it does point to its own address numerically

Dannyu NDos

I was thinking something like this: T *p; p = reinterpret_cast<T*>(&p);

Unrelated String

yeah casts work too :P

Neil