Foreword

Rust is not an easy language to learn. Ask why, and you'll hear that Rust was designed to solve almost any complex problem in system programming, a complicated domain to begin with. It was designed to do it safely, to be incredibly fast, and be very strict; "ease of use" is a necessary sacrifice. Rust reads like any other imperative language, but it incorporates a number of special concepts that ask you to think through your problems in greater depth and with a different spin than you're used to. It's brutally honest about the complicated parts a system language has to address.

Those are the typical reasons cited for why Rust is hard. The more honest answer is that those people may not have the right teacher.

I met Claus at my first event as an open source developer for Microsoft. He had joined just a few months before, and could show me the ropes. It didn't occur to me until a few weeks later that, as his manager, I was supposed to be teaching him! I've discovered that this is a common situation for Claus: he falls naturally into a teaching role. Not a lecturing bore, either—the kind of teaching where the student doesn't realize that's what's happening until they find themselves using newly acquired knowledge. We've long since moved into other roles, but I've seen the pattern repeated over and over again.

Early in his career as an open source developer, Claus found himself diving deep into documentation. And fair enough: it's often the most important part of a project! "Just three lines," he said to me once. "I just lost a whole day of my life because someone didn't bother to write three lines of good documentation. I can fix that."

Claus's background was in academic software development, but in his professional life, he has rejected the dry, abstract computer science theory often taught in that environment. He is one of those rare developers who cares deeply about making this easy for people to understand. It's important that it makes sense, it's important that it looks nice, it's important that it's easy to follow—and how to make it that way is intuitive to him. I think it honestly doesn't occur to him that other people struggle to explain things the way he does naturally.

One of the aspects of this book that I appreciated the most when reading it is the balance Claus strikes. It stays focused on the teaching goal without getting sidetracked by more technical detail than is required. We all know the feeling of reading that kind of documentation—the kind that demands to be skimmed. Most readers, including myself, are simply confused by too much theory or detail at the outset. As Claus puts it, "most teachers make it sound like something really fancy is going on, but, in reality, it's quite simple." 

This practical approach has made Claus an in-demand speaker, community member, and contributor in the Rust world. This book is his next step into teaching for a broader audience, and I'm excited to see its impact.

You've chosen a great teacher! Rust is difficult to learn, but it doesn't have to be. Just ask Claus.

Campbell Vertesi

Principal Software Engineer Manager

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