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--People are not important --

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--There are no people in technology, 
just replaceable components --

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(Laughter)

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Alright let's do this.

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Alright, I'm going to tell
you about what Rust is,

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why Rust is a part of Mozilla's work

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and when it's going to start 
being a part of Mozilla's work.

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Let's begin.

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So Rust is a new programming language

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that has been created inside Mozilla

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and shared with the outside world.

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The goal of it

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is basically

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anytime when you traditionally

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as a developer have

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reached for C++

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because you needed certain guarantees
about performance for example

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we want Rust to be a viable alternative

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in every single case.

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There should be no reason to choose C++

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over Rust

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in the ideal future.

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So it began as a side project

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of a Mozillian named Graydon Hoare

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back in before 2009.

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He started working on it full-time

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in 2009

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because Mozilla saw the
ideas that he had and said

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"We can see how we
could put this into Firefox...

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...and make the product better
if we actually had this language".

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So that's when we started investing
time and resources into it.

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Fast forward a few years

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we now have a team under
the Mozilla Research umbrella

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who's working full-time
on improving the language

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and we released
version 1.0 last year

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and every 6 weeks we
now release a new version

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so we just released 1.13

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and there is a large community

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around the language now

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so not only do we have developers

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working in Mozilla on it

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some of those developers are part
of what's called the Core Team

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and those are the people that
decide the future of the language

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and help shape where
it's going as time goes on

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so in addition to our employees

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we have volunteers

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and employees from other companies

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that are now depending on
Rust for their products

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and they're helping shape this ecosystem

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which then has a large number of libraries

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that are being developed by people

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who are enthusiastic about the language

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it's got a lot of downloads happening
since the last time I gave this talk

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there've been 10 million more downloads
and 300 new libraries published

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so there's a lot going on,
there's also the friends of Rust

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which I'll show you

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there is a page showing lots of different
companies that've told us

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"Yes, we are relying on
Rust in production...

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...we are very excited
about its prospects".

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So, lots of cool things going on there.

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So the reason for Rust

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is that we have in the past

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what 10 or more years of using Firefox

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and Javascript in Firefox

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sorry C++ and Javascript in Firefox

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we've come across the fact that

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there are some pervasive problems

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that are caused by using C++

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that is writing code that
makes use of local threads

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is very difficult

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it's easy to write incorrect code

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and it is very easy to write
code which is unsafe

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and that translates into

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security exploits

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things that are stored by governments

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and by hackers

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all over the world

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and used to

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steal data from users

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and take over their computers

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using the browser as a vector.

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There's a huge number of these
that are released every year

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by security investigators

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and there's competitions showing

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who can pwn a browser the quickest.

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So we looked for ways to address this

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by creating a new language

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and it turns out

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that actually both of these issues

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make it difficult to write parallel code

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that makes use of modern hardware

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and writing code that is
safe and not exploitable

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turns out they can both be addressed

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by introducing the concept of
Ownership in the language.

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So let's talk about what that means.

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Ownership encapsulates two ideas basically

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it is what the owner of a value is

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and whether there are
multiple owners of a value

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or mulitple users that are sharing a value

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and additionally when that
value is actually valid.

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What is the point in the program

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in which it's actually safe
to interact with the value.

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And so from this we can derive a few rules

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that if there is only a
single owner for a value

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that value can be destroyed
when the owner goes out of scope

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because there are no ways to
reference that value anymore

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similarly if a value
has only a single owner

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that means that it is legal to mutate it

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because no one can observe
the change to that value

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and finally

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if you have multiple owners

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you need to have

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something called Borrowing

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which is, you still have a single owner

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but other people can observe it

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but it cant be changed during that time.

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So let's talk about an analogy here,

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if I've got a colouring book and a marker

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and some friends

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we can establish some rules

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the colouring book and
the marker are my property

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so they go with me wherever I go

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if I leave no one else can
observe the book

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or colour in it

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however I am able to loan
the book to someone else

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and that means they're
borrowing it from me

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that also means that I can't colour
in it while they're borrowing it

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because that's rude

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so they can also choose to
lend it to people around them

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but that means that if
anyone else is borrowing it

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they need to give it back
to me before they leave

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because it's my property

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and only I can leave with it.

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Additionally,

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if I have the marker

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I'm able to colour in the book

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if I have the book

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I can also give the marker to someone else

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and that means they can colour
in the book if they have it

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but that means that I'm
no longer able to colour

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because there's only a single marker.

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And finally,

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if I want to leave but I dont actually
have the book in my posession

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there's a problem, either I need to wait
until someone gives me the book back

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or I need to actually give
it to someone else and say

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"OK, it's not my property anymore,
...it's yours to deal with".

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So Ownership in Rust.

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If we have a type we call a ColouringBook

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and it gives us a constructor

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that returns a new instance
of a ColouringBook.

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We can say OK,

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here is a variable called a Book

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which we will say

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stores this ColouringBook value.

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That means that we can now

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call this Colour method

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which will change the
Colouring Book in some way,

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it'll colour in it.

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That's fine, we can mutate it

160
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because we only have a single owner.

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So what happens if

162
00:13:05,415 --> 00:13:06,916
someone borrows the Book?

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We now have another variable
called Borrowed Book

164
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and we use the ampersand

165
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to show that we are borrowing the value

166
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that's stored in this value called Book

167
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- this variable called Book.

168
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This is an Immutable Borrow.

169
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That means that it is not possible

170
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to mutate the original value anymore

171
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because it's borrowed.

172
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So we cannot colour in the book

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while it's borrowed by someone else.

174
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This follows our analogy.

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The other thing however

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is that if someone else is
borrowing the book,

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they also cannot colour in it.

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They don't have the marker.

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In this case they only have
an Mutable Borrow

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so they cannot mutate it.

181
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So we can work around this

182
00:13:50,636 --> 00:13:52,932
by using what's called a Mutable Borrow.

183
00:13:52,932 --> 00:13:53,613
This says OK,

184
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give me the book and
give me the marker

185
00:13:55,876 --> 00:13:58,756
and then they have both those elements

186
00:13:58,756 --> 00:14:01,215
necessary in order
to actually colour in it

187
00:14:01,215 --> 00:14:02,618
and mutate it in this case.

188
00:14:02,618 --> 00:14:03,988
So we have the ampersand

189
00:14:03,988 --> 00:14:05,629
followed by the Mute keyword

190
00:14:05,629 --> 00:14:06,351
and this means

191
00:14:06,351 --> 00:14:08,656
give me a Mutable Borrow

192
00:14:08,656 --> 00:14:10,156
to the value that follows.

193
00:14:13,308 --> 00:14:15,395
However the thing to note here

194
00:14:15,395 --> 00:14:19,005
is that we cannot use
the original variable

195
00:14:19,018 --> 00:14:19,917
called Book

196
00:14:19,917 --> 00:14:21,921
in order to mutate it while it's borrowed.

197
00:14:21,921 --> 00:14:23,634
We cannot have two different
people colouring in it

198
00:14:23,634 --> 00:14:25,774
because only one person
can colour at a time.

199
00:14:29,735 --> 00:14:32,315
So let's go back to the
example we had before.

200
00:14:32,510 --> 00:14:34,250
So we've got a Book value

201
00:14:34,252 --> 00:14:35,544
we're allowed to colour in it

202
00:14:35,544 --> 00:14:37,059
because there's no one borrowing it

203
00:14:37,059 --> 00:14:38,330
then on the next line

204
00:14:38,330 --> 00:14:40,317
we have an Immutable Borrow

205
00:14:41,417 --> 00:14:42,774
and we're not allowed to colour

206
00:14:42,774 --> 00:14:44,195
in the original one again

207
00:14:44,195 --> 00:14:45,115
this is fine

208
00:14:45,126 --> 00:14:46,166
it's borrowed

209
00:14:46,171 --> 00:14:47,451
it can't be coloured in.

210
00:14:48,309 --> 00:14:49,319
So let's fix this

211
00:14:50,300 --> 00:14:52,592
this is where we talk about lifetimes

212
00:14:52,592 --> 00:14:54,255
because remember how I said that

213
00:14:54,255 --> 00:14:56,725
we can figure out
when a value is valid?

214
00:14:56,730 --> 00:14:59,390
So this means that if we have a scope here

215
00:14:59,398 --> 00:15:01,408
deliniated by

216
00:15:01,412 --> 00:15:03,233
the curly braces

217
00:15:03,233 --> 00:15:05,653
this means that inside the curly braces

218
00:15:05,662 --> 00:15:08,002
anything that is unique inside there

219
00:15:08,032 --> 00:15:10,292
no longer exists outside of them.

220
00:15:10,298 --> 00:15:12,408
So if we create this Borrowed Book value

221
00:15:12,415 --> 00:15:14,880
and we borrow from the Book value

222
00:15:14,880 --> 00:15:16,859
we have a Mutable Borrow

223
00:15:16,859 --> 00:15:18,179
and that's fine

224
00:15:18,222 --> 00:15:19,529
we can then do something with this

225
00:15:19,529 --> 00:15:21,079
that doesn't require mutating it

226
00:15:21,092 --> 00:15:23,780
we can just look through the
Book, we can investigate it,

227
00:15:24,030 --> 00:15:26,203
and that doesn't mutate it, that's fine.

228
00:15:26,313 --> 00:15:29,946
And so previously calling Colour
on the original Book value

229
00:15:29,946 --> 00:15:31,045
would've been an error

230
00:15:31,045 --> 00:15:32,139
because it was borrowed

231
00:15:32,139 --> 00:15:34,058
but now the borrow no longer exists

232
00:15:34,058 --> 00:15:37,186
because it is only valid within
the scope of these braces.

233
00:15:37,186 --> 00:15:38,676
This is how we can control

234
00:15:38,682 --> 00:15:40,532
the scope of a Borrow.

235
00:15:43,385 --> 00:15:45,603
So finally we can also transfer Ownership.

236
00:15:45,603 --> 00:15:49,017
This is how we talk about giving
away the Book to someone else.

237
00:15:49,017 --> 00:15:51,097
By default we can say OK,

238
00:15:52,213 --> 00:15:54,233
we'll create a new variable called Book 2

239
00:15:54,238 --> 00:15:57,218
and it will have the contents
of the Book variable

240
00:15:57,652 --> 00:15:59,176
and we can now colour in Book 2.

241
00:15:59,176 --> 00:16:01,839
That's fine, it's not a borrow
there's no ampersand there

242
00:16:01,839 --> 00:16:03,804
we are giving control of the value

243
00:16:03,814 --> 00:16:05,204
to another variable

244
00:16:07,206 --> 00:16:08,028
and additionally

245
00:16:08,028 --> 00:16:10,108
if you try to compile this
you'll note that

246
00:16:10,108 --> 00:16:12,602
we can no longer interact
with the Book variable

247
00:16:12,606 --> 00:16:14,606
because we transfered Ownership

248
00:16:14,607 --> 00:16:15,977
it doesn't exist anymore

249
00:16:15,992 --> 00:16:17,728
the compiler knows this and can say

250
00:16:17,728 --> 00:16:20,206
"Nope, that is not safe
what you're trying to do".

251
00:16:21,612 --> 00:16:25,274
And you'll note the link up here
actually goes to a playground

252
00:16:25,274 --> 00:16:28,050
where you can play with the
Rust compiler in your browser

253
00:16:28,050 --> 00:16:31,857
and there's a sample for this code
that you can experiment with there

254
00:16:31,857 --> 00:16:33,385
already prepared for you.

255
00:16:35,722 --> 00:16:36,452
So

256
00:16:37,028 --> 00:16:39,238
we understand Borrowing
a little bit better now

257
00:16:39,238 --> 00:16:41,068
especially with the analogy

258
00:16:41,078 --> 00:16:43,088
but how does this
actually help in practice?

259
00:16:43,088 --> 00:16:45,779
How does this address the two
cases we talked about before?

260
00:16:45,779 --> 00:16:48,418
Using values after they're no longer valid

261
00:16:48,915 --> 00:16:56,055
and writing code that works with
multiple threads at the same time.

262
00:16:56,561 --> 00:16:57,271
So first

263
00:16:57,785 --> 00:17:01,075
with Use-after-free problems

264
00:17:02,429 --> 00:17:04,571
those happen in C++

265
00:17:04,571 --> 00:17:07,551
because you'll have pointers in your code

266
00:17:07,762 --> 00:17:09,433
but the pointers are not associated

267
00:17:09,433 --> 00:17:11,180
with the value they're pointing to.

268
00:17:11,180 --> 00:17:12,770
So you could delete

269
00:17:12,779 --> 00:17:15,057
the memory that they're pointing to

270
00:17:15,057 --> 00:17:17,214
but the pointers are still
pointing at that memory

271
00:17:17,214 --> 00:17:19,747
and so if you aren't careful
you can end up using pointers

272
00:17:19,747 --> 00:17:21,031
that are pointing to invalid memory.

273
00:17:21,373 --> 00:17:22,423
So in Rust

274
00:17:22,433 --> 00:17:24,263
the compiler is actually tracking this

275
00:17:24,539 --> 00:17:26,819
so it doesn't let you write code

276
00:17:26,836 --> 00:17:28,426
that has the potential

277
00:17:29,017 --> 00:17:32,385
where pointers could point at
memory that no longer is valid

278
00:17:32,736 --> 00:17:33,986
and that means that

279
00:17:33,988 --> 00:17:37,108
you're always taking
borrowed pointers to values

280
00:17:37,767 --> 00:17:39,090
where the compiler says

281
00:17:39,090 --> 00:17:41,263
"OK. I know exactly how
long this value is valid for...

282
00:17:41,263 --> 00:17:45,103
...because I know what the owner
is and therefore any pointers to it...

283
00:17:45,108 --> 00:17:51,358
...must no longer exist before
the owner no longer exists"

284
00:17:54,240 --> 00:17:55,030
and additionally

285
00:17:55,037 --> 00:17:56,459
you can also

286
00:17:56,459 --> 00:17:59,820
because the Rust compiler also
tracks outstanding Borrows

287
00:17:59,820 --> 00:18:00,913
you can also say

288
00:18:00,913 --> 00:18:04,543
"OK, we are guaranteed that
there's no way to mutate this...

289
00:18:04,543 --> 00:18:08,474
...while anyone else is borrowing
and trying to look at the value"

290
00:18:08,474 --> 00:18:10,403
and this addresses another case

291
00:18:10,403 --> 00:18:12,063
where this can happen in C++

292
00:18:12,063 --> 00:18:14,768
where you end up changing the value

293
00:18:14,768 --> 00:18:18,652
like reallocating a pointer or something
while other things are trying to point to

294
00:18:18,652 --> 00:18:20,471
memory that it was relying on

295
00:18:21,419 --> 00:18:23,940
and as for parallel code
with multiple threads

296
00:18:25,450 --> 00:18:27,230
the issue arises with Data Races

297
00:18:27,242 --> 00:18:28,872
where you have multiple threads

298
00:18:28,879 --> 00:18:31,571
that are sharing values and
they're also mutating them.

299
00:18:31,571 --> 00:18:34,351
It's the same issue we
just talked about basically

300
00:18:34,362 --> 00:18:36,541
where they're not
coordinated in figuring out

301
00:18:36,541 --> 00:18:39,776
when it's safe to write to a value and
when it's safe to read from a value

302
00:18:39,776 --> 00:18:41,716
because you might get intermediate values

303
00:18:41,716 --> 00:18:43,806
when the write hasn't completed yet.

304
00:18:44,296 --> 00:18:49,776
So Rust addresses this by forcing you
to either transfer ownership of values

305
00:18:49,781 --> 00:18:51,346
that another thread needs to use

306
00:18:51,346 --> 00:18:53,926
so that two threads cannot
share the same value

307
00:18:53,932 --> 00:18:55,030
or

308
00:18:55,030 --> 00:18:57,960
ensuring that any values that you
do share between the threads

309
00:18:57,960 --> 00:18:59,433
abide by certain restrictions

310
00:18:59,433 --> 00:19:01,784
that prevent invalid writes from happening

311
00:19:01,784 --> 00:19:03,654
and invalid reads from happening

312
00:19:03,654 --> 00:19:05,384
so that races can't happen

313
00:19:05,388 --> 00:19:10,978
and it's impossible to write code that
is not actually thread safe.

314
00:19:13,479 --> 00:19:14,179
So

315
00:19:14,191 --> 00:19:15,478
how this actually applies

316
00:19:15,478 --> 00:19:17,223
to what we're doing at Mozilla

317
00:19:17,223 --> 00:19:19,616
is that we've got the Mozilla
Research organisation

318
00:19:19,616 --> 00:19:22,968
and so part of them are working
on improving Rust the language.

319
00:19:22,968 --> 00:19:24,658
However another part of them

320
00:19:24,658 --> 00:19:26,918
are working on building a
brand new web browser

321
00:19:26,933 --> 00:19:28,643
because Firefox is not enough.

322
00:19:29,360 --> 00:19:30,950
This one's called Servo

323
00:19:30,960 --> 00:19:33,210
and so we're building it
from the ground up

324
00:19:33,479 --> 00:19:35,339
and the reason we're doing this is that

325
00:19:35,339 --> 00:19:36,969
there are decisions that were made

326
00:19:36,969 --> 00:19:38,522
design decisions for Firefox

327
00:19:38,533 --> 00:19:40,213
that were made a decade ago

328
00:19:40,213 --> 00:19:44,203
which are very difficult to
change at this point in time

329
00:19:44,217 --> 00:19:45,927
it'd be a huge amount of work

330
00:19:45,930 --> 00:19:48,499
to redesign parts of Firefox
we think could be better

331
00:19:48,499 --> 00:19:49,862
but it's also difficult

332
00:19:49,868 --> 00:19:53,337
to verify whether that would be

333
00:19:53,337 --> 00:19:55,927
a worthwhile use of time
without actually doing it

334
00:19:55,927 --> 00:19:58,169
so we compromise by creating
a brand new browser

335
00:19:58,169 --> 00:20:00,089
where we can actually try out new ideas

336
00:20:00,089 --> 00:20:02,753
and give ourselves a playground
to experiment with things

337
00:20:02,753 --> 00:20:05,373
we could do better in Firefox
and if they work out great

338
00:20:05,373 --> 00:20:10,117
we can then start transferring them
back into Firefox and integrate them

339
00:20:10,121 --> 00:20:11,073
and additionally

340
00:20:11,073 --> 00:20:12,663
this means that we can experiment

341
00:20:12,663 --> 00:20:16,939
with letting out pages

342
00:20:16,939 --> 00:20:18,439
doing that in parallel

343
00:20:18,439 --> 00:20:20,552
rather than all other browsers today

344
00:20:20,552 --> 00:20:22,962
which do them sequentially
and single-thread

345
00:20:22,975 --> 00:20:24,415
we can do things

346
00:20:24,428 --> 00:20:25,980
like experiment with the way

347
00:20:25,980 --> 00:20:27,049
that we

348
00:20:27,049 --> 00:20:28,399
redraw things to the screen

349
00:20:28,399 --> 00:20:30,269
and do it more like a computer game

350
00:20:30,865 --> 00:20:33,473
we can do things like change the way

351
00:20:33,473 --> 00:20:35,662
that we're managing memory

352
00:20:35,662 --> 00:20:37,792
for the parts of the web page

353
00:20:37,792 --> 00:20:40,409
so that it's more integrated
with the garbage collection

354
00:20:40,409 --> 00:20:41,801
that the Javascript code

355
00:20:41,809 --> 00:20:43,829
ends up ineracting with

356
00:20:43,847 --> 00:20:46,306
so all of this are things
that we're doing in Servo

357
00:20:46,306 --> 00:20:48,026
and we're getting some great results

358
00:20:48,032 --> 00:20:49,602
and some of them are already

359
00:20:49,602 --> 00:20:51,958
being integrated back into Firefox.

360
00:20:53,434 --> 00:20:55,504
So we're already shipping foot code today

361
00:20:55,505 --> 00:20:57,495
in Firefox that's written in Rust.

362
00:20:57,767 --> 00:21:00,360
For example we have parts
of our Media Stack where

363
00:21:00,360 --> 00:21:06,510
we have code that's just responsible
for reading parts of video files

364
00:21:06,510 --> 00:21:09,498
which has been a source of security
vulnerabilities in the past

365
00:21:09,498 --> 00:21:11,623
and there's no reason
that should be the case

366
00:21:11,623 --> 00:21:13,153
so we rewrite it in Rust

367
00:21:13,153 --> 00:21:14,973
and we get safety by default.

368
00:21:14,979 --> 00:21:16,756
So that's shipping in Firefox today.

369
00:21:16,756 --> 00:21:18,887
We've also got a project called Oxidation

370
00:21:18,887 --> 00:21:21,077
which is a list on the wiki

371
00:21:21,085 --> 00:21:23,946
of all the pieces that
we're in the process

372
00:21:23,946 --> 00:21:27,266
of writing in Rust in Firefox today

373
00:21:27,660 --> 00:21:29,270
some of the most challenging ones

374
00:21:29,270 --> 00:21:30,067
that I mentioned previously

375
00:21:30,067 --> 00:21:31,526
the Rendering Engine

376
00:21:31,526 --> 00:21:34,976
the Style System and Layout

377
00:21:34,976 --> 00:21:37,096
those are being integrated
into Firefox today

378
00:21:37,096 --> 00:21:38,876
as part of the Quantum Project

379
00:21:38,881 --> 00:21:40,815
and so you can basically expect that

380
00:21:40,815 --> 00:21:42,818
the amount of Rust code in Firefox

381
00:21:42,818 --> 00:21:44,091
will increase over time

382
00:21:44,091 --> 00:21:47,161
there's been a lot of really good
results panning out so far

383
00:21:48,190 --> 00:21:50,220
especially for areas where

384
00:21:50,220 --> 00:21:52,332
they shouldn't be security sensitive

385
00:21:52,332 --> 00:21:54,512
that they need to be high performance

386
00:21:54,522 --> 00:21:56,512
those could be great places

387
00:21:56,512 --> 00:21:58,330
for integrating Rust code

388
00:21:58,330 --> 00:22:01,070
because you've got those by default

389
00:22:03,611 --> 00:22:05,568
so if you'd like to know more about Rust

390
00:22:05,568 --> 00:22:06,774
and Mozilla

391
00:22:06,774 --> 00:22:09,437
you can check out the Rust
Playground I mentioned earlier

392
00:22:09,437 --> 00:22:12,158
that allows you to experiment
with writing Rust code

393
00:22:12,158 --> 00:22:13,196
in your browser

394
00:22:13,196 --> 00:22:14,821
we've got a nice introductory book

395
00:22:14,821 --> 00:22:17,539
that covers everything you need
to know about the language

396
00:22:17,539 --> 00:22:19,279
called The Rust Programming Language

397
00:22:19,279 --> 00:22:23,002
which is accessible from the language
website and we've got IRC channels

398
00:22:23,002 --> 00:22:26,846
which are designed for both beginners
who like to interact with other people

399
00:22:26,846 --> 00:22:29,735
who really want to answer
your questions right there

400
00:22:29,735 --> 00:22:32,480
as well as a huge community
in the Rust channel

401
00:22:32,480 --> 00:22:35,480
who really adore asking
and answering questions.

402
00:22:36,935 --> 00:22:37,645
That's all.

403
00:22:37,645 --> 00:22:38,737
Thank you very much.

404
00:22:39,519 --> 00:22:42,099
[Applause]

405
00:22:42,099 --> 00:22:43,361
Any questions?

406
00:22:48,839 --> 00:22:49,609
Yes

407
00:22:53,159 --> 00:22:56,399
What would be a good way to
start contributing or participating?

408
00:22:57,275 --> 00:22:59,020
There's a few ways

409
00:22:59,020 --> 00:23:02,120
so if there are

410
00:23:04,838 --> 00:23:05,608
let me see

411
00:23:05,608 --> 00:23:08,699
if there are libraries that you
would like to use from Rust

412
00:23:08,699 --> 00:23:09,919
that don't exist yet

413
00:23:11,297 --> 00:23:14,104
writing either libraries
from scratch in Rust

414
00:23:14,104 --> 00:23:16,106
to scratch that itch

415
00:23:16,106 --> 00:23:16,824
very handy

416
00:23:16,824 --> 00:23:18,395
publishing that for the community

417
00:23:18,395 --> 00:23:21,926
or if there are libraries
written in C which already exist

418
00:23:21,926 --> 00:23:25,312
which would give you functionality
but don't exist in Rust yet

419
00:23:25,312 --> 00:23:26,907
then writing bindings in Rust

420
00:23:26,907 --> 00:23:30,247
around a C library

421
00:23:30,258 --> 00:23:31,668
is very useful

422
00:23:32,766 --> 00:23:35,601
because that allows you to
build safer abstractions

423
00:23:35,601 --> 00:23:38,376
on top of things that would
otherwise be potentially unsafe

424
00:23:38,376 --> 00:23:40,626
but is really easy to
integrate with C code

425
00:23:40,626 --> 00:23:44,673
which is one reason why it's working
out so well to integrate Rust in Firefox.

426
00:23:46,871 --> 00:23:49,347
There's lots of other suggestions
on the Rust website

427
00:23:49,347 --> 00:23:52,467
of ways to participate in
the Rust Community

428
00:23:53,007 --> 00:23:54,607
if that's what you're asking.

429
00:23:58,077 --> 00:23:59,177
Yes Lucy?

430
00:24:15,822 --> 00:24:19,192
What are the most compelling
reasons for someone to learn

431
00:24:19,209 --> 00:24:24,859
the language and potentially start
participating and contributing?

432
00:24:27,193 --> 00:24:29,243
One thing I've heard
is that actually people

433
00:24:29,246 --> 00:24:32,196
who don't already have what's called

434
00:24:32,201 --> 00:24:33,848
systems programming experience

435
00:24:33,848 --> 00:24:36,888
so a lot of experience
using C++ for example

436
00:24:36,895 --> 00:24:38,876
one of the lower level languages

437
00:24:38,876 --> 00:24:41,148
people coming from a web
development background

438
00:24:41,148 --> 00:24:43,829
people writing a lot of 
Javascript, Ruby, Python

439
00:24:44,807 --> 00:24:47,520
what I've heard is that people
coming from those languages

440
00:24:47,520 --> 00:24:50,620
are actually getting
their first experience

441
00:24:50,633 --> 00:24:52,523
doing low level programming stuff

442
00:24:54,074 --> 00:24:57,504
but in a way which is much less daunting

443
00:24:57,510 --> 00:24:59,410
than C or C++

444
00:24:59,416 --> 00:25:02,811
where they know that the
compiler has their back

445
00:25:02,811 --> 00:25:06,139
in ways that the compilers
for C++, for example, don't

446
00:25:06,390 --> 00:25:08,229
and it will tell you when
you're making mistakes

447
00:25:08,229 --> 00:25:10,284
and it won't let you make those mistakes

448
00:25:10,284 --> 00:25:11,434
which is pretty exciting.

449
00:25:14,993 --> 00:25:17,703
There are two people who I know

450
00:25:17,705 --> 00:25:20,086
who come from Ruby

451
00:25:20,086 --> 00:25:21,269
Javascript backgrounds

452
00:25:21,269 --> 00:25:23,489
who are now putting together

453
00:25:23,504 --> 00:25:25,258
a series of tutorials

454
00:25:25,258 --> 00:25:28,238
for teaching people how to do
kernel programming using Rust

455
00:25:29,534 --> 00:25:32,247
with the intention that other
people are coming from those

456
00:25:32,247 --> 00:25:34,097
high level backgrounds

457
00:25:34,097 --> 00:25:35,949
and trying this out for the first time

458
00:25:35,949 --> 00:25:39,609
so there's a lot of ways to experiment
with things that traditionally has been

459
00:25:39,609 --> 00:25:41,167
rather unapproachable

460
00:25:41,179 --> 00:25:44,279
for large segments of the
developer population.

461
00:25:49,791 --> 00:25:52,361
Pretty compelling reason really

462
00:25:52,361 --> 00:25:55,364
and even if you do have
experience doing C++

463
00:25:55,364 --> 00:25:57,134
and lower level things like that

464
00:25:59,139 --> 00:26:02,246
I find that not having to worry
about whole classes of problems

465
00:26:02,246 --> 00:26:03,297
you can make

466
00:26:03,297 --> 00:26:06,414
as a developer in those languages

467
00:26:06,414 --> 00:26:07,731
makes a huge difference

468
00:26:07,731 --> 00:26:10,311
it allows you to reason
about your code better

469
00:26:10,326 --> 00:26:13,726
it allows you to be more
adventurous with your code.

470
00:26:15,255 --> 00:26:34,935
(Inaudible audience discussion)

471
00:26:39,632 --> 00:26:41,392
So the questions was

472
00:26:41,837 --> 00:26:44,147
one of the things people have talked about

473
00:26:45,255 --> 00:26:49,815
is that Rust should be able to make
the process of refactoring your code

474
00:26:50,422 --> 00:26:54,252
easier, safer, generally less complicated

475
00:26:54,252 --> 00:26:55,956
and less uncertain

476
00:26:55,956 --> 00:26:58,426
and has there been talk of that

477
00:26:58,431 --> 00:27:00,147
has there been evidence of that

478
00:27:00,147 --> 00:27:00,891
and yes

479
00:27:00,891 --> 00:27:02,851
there's actually a really great blog post

480
00:27:02,858 --> 00:27:04,008
in the past couple weeks

481
00:27:04,024 --> 00:27:05,684
of someone who was

482
00:27:05,689 --> 00:27:07,529
refactoring their code

483
00:27:07,546 --> 00:27:11,696
and the compiler kept pointing out
ways in which it would not be safe

484
00:27:11,696 --> 00:27:13,786
to refactor it in that certain way

485
00:27:13,800 --> 00:27:16,032
because it was shared between threads

486
00:27:17,342 --> 00:27:18,597
like he would fix that thing

487
00:27:18,597 --> 00:27:20,507
and it would go down the 
rabbit hole a little bit further

488
00:27:20,507 --> 00:27:22,610
and say "Oh now this isn't safe anymore".

489
00:27:22,610 --> 00:27:26,280
and was this very compiler
guided refactoring session

490
00:27:26,303 --> 00:27:27,493
which he wrote about

491
00:27:27,511 --> 00:27:29,561
and documented top to bottom

492
00:27:29,575 --> 00:27:32,085
and it's great, it seems to just

493
00:27:32,090 --> 00:27:33,008
verify the premise

494
00:27:33,008 --> 00:27:36,968
that this does prevent you
from making mistakes.

495
00:27:43,380 --> 00:27:44,950
Alright let's call it there.

496
00:27:44,973 --> 00:27:47,073
Thank you for attending everybody

497
00:27:47,073 --> 00:27:50,283
[Applause]