Back to Basics: Templates in C++ - Nicolai Josuttis - CppCon 2022

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Back to Basics: Templates in C++ - Nicolai Josuttis - CppCon 2022
github.com/CppCon/CppCon2022
Templates are among the most powerful features of C++, but they remain misunderstood and underutilized, even as the C++ language and development community have advanced. This talk shows when and how to use modern templates to build software that's cleaner, faster, more efficient, and easier to maintain. We will cover all basic aspects of templates you have to know when programming generic code in Modern C++
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Nicolai Josuttis
Nicolai Josuttis is well-known in the community for his authoritative books and talks. For more than 20 years he has been a member of the C++ Standard Committee. He is the author of several worldwide best-sellers, including:
- C++20: The Complete Guide
- C++17: The Complete Guide
- C++ Move Semantics: The Complete Guide
- The C++ Standard Library: A tutorial and Reference
- C++ Templates: The Complete Guide (w/ David Vandevoorde & Doug Gregor)
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#cppcon #programming #template

[@moderncpp]

Great talk. I believe that understanding templates reveals most of the C++ programming language.

[@superscatboy]

Nico is a great speaker, I've been looking forward to this one!

[@deadbird99]

Hands down the best templates course I've ever had. Thanks!!

[@wigglyk2796]

Wow the master himself. His book on templates is excellent. Thanks for this video.

[@CppCon]

Glad to hear that you enjoyed this presentation!

[@MyLucjusz]

That's a pure pleasure to listen to the prelection like this. Thank you!

[@prafulsrivastava7684]

This is exactly what I was looking for! Great talk!

[@Tony-tu8uz]

Very good! Thank you for the talk!

[@brandonz6121]

A truly insightful talk!

[@parthapratimmukherjee]

Its amazing how Nico can make extremely complex topics approachable. I bought all his books!

[@richardvonlehe4581]

Well done! Engaging throughout.

[@yowadup1000]

Looks pretty exciting!

[@NickEnchev]

Excellent talk, thank you.

[@OptimusVlad]

Wow, this is trippy. Didn't know this was a thing:
if constexpr (requires {coll.push_back(val);})

[@flocela]

thank you. even better the second time around! : )

[@xFabi99]

Templates are pretty awesome now, as is this talk ;)

[@viacheslav1392]

Great talk man!

[@paulselormey7862]

Josuttis, thank you.

[@the_real_foamidable]

Very cool talk. Always good to recapitulate the basics - there are to many things we use without understanding the underlying tech and history.
BTW: Where can I get this awesome T-Shirt?

[@mahdies56]

Great talk

[@ssmondal007]

Super Sir, impressed :)

[@Jam18123]

Very useful

[@ZackDia-Ptr]

Good stuff...

[@dark808bb8]

We need an "if compiles{" expression that takes the first branch if the code in that branch compiles 😅

[@chudchadanstud]

The much needed. We need better metaprogramming.

[@xudongsun]

love his tshirt. where can I get one?

[@MalcolmParsons]

35:46 std::complex is only specified for float, double and long double, not for int.

[@sanjaygatne1424]

nice talk.
i had one query on slide no.31, why recursive call to "if" statement when you know number of var args. why not "range for".

[@thepiratepeter4630]

You can't iterate on an argument pack like you would do with a container, because the types of the various elements could be different.

[@thepiratepeter4630]

In his specific example you could avoid recursion using a fold expression.

[@atib1980]

There isn't a foreach construct in C++ that would allow you to loop through a range of data of different data types at runtime. C++ foreach works on only those data types that have implemented the basic input iterator related operators defined by the requirements of input iterators (begin(), end() operator++() and operator*). In the example on slide 31 you just want to print every fn argument on a separate line (where fn argument is of a certain type for which ostream& operator

[@djupstaten2328]

This is why a TypeEval function is screaming to be created. I am 100% certain the std::people can create a better one than I can. Typeid() doesn't actually consider a tuple of string/int/string the same type as a tuple of variant/variant/map as the same types so there is no secure way to funnel them into whatever place or process they need to be. A bool function is totally fine as long as it is general (i.e. one container type instance should match with another, and with its type-name, regardless of their particular flavor of chaos inside). Knowing everything at compile time is neither realistic nor creatively workable. "Strongly typed" needs to not just be a begrudging neurosis or a religious mantra but also lead to supplying the proper tools for the coder to secure this strength on his or her end.

[@BiddutMitra]

C with better structure, which is c++.

[@ifeanyioraelosi7305]

Interesting talk, though not as 'basic' as I assumed.
It would have been helpful if the speech bubbles were removed; the code in the speech bubbles could have been placed side-by-side with the code on the left. For example, at 4:18, the text in the speech bubble could have been replaced with the code on the left but with "T" and "typename" swapped out for "CustomType" and "class". The explanation need not change.
4:16 "...use a better name, like CustomType as shown in the example on the right".
3:37 "...can be replaced by class, as you can see in the example on the right..."
Edit: I just noticed the speech bubbles do help as annotations in other slides.

[@kuijaye]

It feels, to me, i have to know all of c++. Idk why. Whenever he waives his hands on some somewhat deprecated or irrelavant topics or on some dark corners, i t feels unsatisfactory...

[@vasylvoina6663]

I call function templates for 145 000 different types, so I end up with 145 000 functions generated. Wow, really nice feature.

[@yseeme]

Keep C++ away from stupid politics

[@__hannibaalbarca__]

_CppCon_ please keep politic out.