STL std::span | Modern Cpp Series Ep. 115

[@thestarinthesky_]

@7:57 I guess when you pass a span with a static extent to a function that accepts a span with a dynamic extent, the span within the function has a dynamic extent, regardless of the original span's extent. This is because the type of the parameter param in your function PrintArray is std::span, which defaults to std::span. So within the function, param.extent is std::dynamic_extent, even though the original span had a static extent.

[@thestarinthesky_]

Thanks Mike for covering C++ 20 features. Looking forward to std::range as well :) I am glad C++ continues growing and evolving.

[@MikeShah]

Cheers!

[@thestarinthesky_]

It seems we can use std::span for C-style array too. So when we pass a C-Style array to a function or method, we can use std::span to prevent pointer decay with the benefit of getting the size of using std::span's size method! Cool!

[@MikeShah]

Correct! This is one of the great things about span :)

[@bsdooby]

Maybe relate this concept to `std::string_view`; as such one appreciates the similarities (purpose) more.

[@thestarinthesky_]

Thanks!

[@MikeShah]

Thank you again for this generous gift!

[@LeonardoSalvatore]

Thanks

[@MikeShah]

Thank you for your support! Cheers!

[@LeonardoSalvatore]

@@MikeShah thank you for your work. Cheers!

[@MehmedUlusay]

Thanks, but 14:44 it’s wrong that span is read-only view. We can modify the underlying array with span.

[@MikeShah]

True, can indeed modify the underlying data.

[@robertstrickland9722]

Have you tried, and had issues with, utilizing any of the C++20 functionality in the new M-series Macbooks? I was reading about std::span and template concepts and when I tried to compile some test code, clangd on my macbook would always fail and it turns out that none of those c++20 features were available. I seemed to have a pretty up to date version of clang yet still nothing. C++20 STL libraries work just fine on my Linux machine.

[@MikeShah]

Might need to update your version of clang perhaps? Haven't had issues for anything c++20 related. I think MSVC at this time is the compiler supporting more of the C++23 features.

[@kevinzebb]

Any chance you’d be willing to show or give insight into work you’ve done in the past or are currently doing? I like these videos but it would be interesting to see how they’re applied in real world applications with a narration as to prevent confusion or getting lost when one reads by ones self.

[@MikeShah]

Thinking about more project-based work after this series gets to a point where videos can slow down 🙂

[@mehtubbhai9709]

I am looking forward to it👍

[@theintjengineer]

Another amazing video. THANK YOU. Greetings from Germany.

[@MikeShah]

Cheers! Thank you!

[@tourdesource]

Really enjoyed the lesson, Mike! That was a lot of "here" though 😁were you nervous?

[@MikeShah]

Cheers! 😛

[@VoidloniXaarii]

Thanks a lot, this had many helpful insights

[@MikeShah]

Cheers!

[@VoidloniXaarii]

@@MikeShah 干杯，威士忌

[@StefaNoneD]

I will never understand why developers don't use autocompletion. The amount of compile errors you'll get when you type everything manually or the time to look for documentation, is not justifiable.

[@MikeShah]

Large projects autocomplete is a good idea. Teaching and learning it's a distraction and the error messages are sometimes useful to decipher live 🙂

[@majorsuchodolski1254]

Nice!

[@MikeShah]

Cheers!

[@codigo-nodosyvfx]

Great video

[@MikeShah]

Cheers!

[@victoreijkhout7115]

Why don't you demonstrate the non-owning aspect? Set an element in the span, see that it's changed in the original. That's the whole point of span. so your remark about read-only at the end is also beside the point.

[@MikeShah]

Fair point! span probably deserves another video as it is a potentially safer and equally efficient way to pass around data.

[@guoliangwang4826]

msbuild 'mySpan.extent' output a large number