This is a clip from a conversation with Bjarne Stroustrup from Nov 2019. New full episodes are released once or twice a week and 1-2 new clips or a new non-podcast video is released on all other days. You can watch the full conversation here: https://www.youtube.com/watch?v=uTxRF5ag27A
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Bjarne Stroustrup is the creator of C++, a programming language that after 34 years is still one of the most popular and powerful languages in the world. Its focus on fast, stable, robust code underlies many of the biggest systems in the world that we have come to rely on as a society. If you're watching this on YouTube, many of the critical back-end component of YouTube are written in C++. Same goes for Google, Facebook, Amazon, Twitter, most Microsoft applications, Adobe applications, most database systems, and most physical systems that operate in the real-world like cars, robots, rockets that launch us into space and one day will land us on Mars.

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So is there differences in your view, not saying which is better or so on, but differences in the different implementations of C++?

Why are there several sort of maybe naive questions for me?

most languages had multiple implementations.

Because if you run on IBM, if you run on a Sun, if you run on a Motorola,

they each have their own compilation structure and their old compilers.

that other people would write compilers for C++ if I was successful.

I wanted to utilize all the backend infrastructures

I soon realized that my users were using 25 different linkers.

linkers and also get any work done on the language.

a world where there was many linkers, many optimizers, many compiler front ends, not to start, but many operating systems.

The whole world was not an 86 and a Linux box or something, whatever is the standard today.

So basically, I assumed there would be lots of compilers.

It was not a decision that there should be many compilers.

And today, there's at least 4 front ends, Clang, GCC, Microsoft, and EDG, it is design group.

They supply a lot of the independent organizations and the embedded systems industry.

We have to think about how many dozen backends there are.

Because different machines have different things, especially in the embedded world, the machines are very different, the architectures are very different.

And so having a single implementation was never an option.

Now I also happen to dislike monocultures.

dangerous because whoever owns the monoculture can go stale and there's no competition and there's no incentive to innovate.

There's a lot of incentive to put barriers in the way of change because, hey, we own the world and it's a very comfortable world for us and who are you to mess with that?

So I really am very happy that there's 4 front ends for C++.

Clang's great, but GCC was great, but then it got somewhat stale.

Clang came along and GCC is much better now.

At least a low number of front-end puts a lot of pressure on standards compliance and also on performance and error messages and compile time speed, all this good stuff that we want.

Do you think, crazy question, there might come along, do you hope there might come along implementation of C++ written, given all its history, written from scratch?

Well, Clang and LLVM is more or less written by from scratch.

Sooner or later, somebody is going to try again.

There has been attempts to write new C++ compilers and some of them has been used and some of them has been absorbed into others and such.


Speaker 0: So is there differences in your view, not saying which is better or so on, but differences in the different implementations of C++? Why are there several sort of maybe naive questions for me? GCC, Clang, so on.

Speaker 1: This is a very reasonable question.

Speaker 2: When I designed C++,

Speaker 1: most languages had multiple implementations. Because if you run on IBM, if you run on a Sun, if you run on a Motorola,

Speaker 2: there was just many, many companies and

Speaker 1: they each have their own compilation structure and their old compilers. It was just fairly common that

Speaker 2: there was many of them. And I wrote C front, assuming

Speaker 1: that other people would write compilers for C++ if I was successful. And furthermore,

Speaker 2: I wanted to utilize all the backend infrastructures

Speaker 1: that were available. I soon realized that my users were using 25 different linkers.

Speaker 2: I couldn't write my own linker. Yes, I could, but I couldn't write 25

Speaker 1: linkers and also get any work done on the language.

Speaker 2: And so it came from

Speaker 1: a world where there was many linkers, many optimizers, many compiler front ends, not to start, but many operating systems. The whole world was not an 86 and a Linux box or something, whatever is the standard today. In the old days, they said a set of X. So basically, I assumed there would be lots of compilers. It was not a decision that there should be many compilers.

It was just a fact. That's the way the world is.

Speaker 2: And yes, many compilers emerged. And today, there's at least 4 front ends, Clang, GCC, Microsoft, and EDG, it is design group. They supply a lot of the independent organizations and the embedded systems industry. And there's lots and lots of backends. We have to think about how many dozen backends there are.

Because different machines have different things, especially in the embedded world, the machines are very different, the architectures are very different. And so having a single implementation was never an option. Now I also happen to dislike monocultures.

Speaker 0: Monocultures. They are

Speaker 1: dangerous because whoever owns the monoculture can go stale and there's no competition and there's no incentive to innovate. There's a lot of incentive to put barriers in the way of change because, hey, we own the world and it's a very comfortable world for us and who are you to mess with that? So I really am very happy that there's 4 front ends for C++. Clang's great, but GCC was great, but then it got somewhat stale. Clang came along and GCC is much better now.

Speaker 0: Competition is good.

Speaker 1: Microsoft is much better now. At least a low number of front-end puts a lot of pressure on standards compliance and also on performance and error messages and compile time speed, all this good stuff that we want.

Speaker 0: Do you think, crazy question, there might come along, do you hope there might come along implementation of C++ written, given all its history, written from scratch? So written today from scratch?

Speaker 1: Well, Clang and LLVM is more or less written by from scratch.

Speaker 0: But there's been C++ 11, 14, 17, 20. You know, there's been a lot of...

Speaker 1: Sooner or later, somebody is going to try again. There has been attempts to write new C++ compilers and some of them has been used and some of them has been absorbed into others and such. Yeah, it'll happen. You

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Bjarne Stroustrup: C++ Implementations - Clang, GCC, Microsoft, and EDG