Classes Part 22 - Curly brace versus parenthesis and std::initializer_list| Modern cpp Series Ep. 59

[@RakVish]

Pheewwwww. This was exactly what was needed. A concise but complete explanation about how the two versions work. Especially that last point showing that the parameterized constructor gets called when the initializer_list version of a constructor does not exist!!

[@MikeShah]

Cheers!

[@AlmondAxis987]

As a self-taught c++ programmer, this was really useful. I always wondered how libraries used curly braces for Container classes like rectangles, points, or RGBA colors. Thanks!

[@MikeShah]

Cheers!

[@utkrystal45]

Well, I will surely recommend this video to my friends starting out with classes and want to have a deep understanding of initializer_list and curly braces. So, well taught by you, Sir!

[@MikeShah]

Cheers!

[@lemuener]

Thanks Mike for the Course I'm learning a lot of new things , very easy to understand your explanations... Thanks a lot.

[@MikeShah]

You are most welcome!

[@dwolrdcojp]

Clear and easy to understand example. Thanks as always!

[@MikeShah]

You are most welcome, thank you for the continued kind words!

[@dhanushs1802]

Very neatly explained as always. Thank You.

[@MikeShah]

Cheers thank you for the kind words!

[@propov1802]

Hey, I got a question. At 2:27 Why do you print them by reference on primitive types? Wouldn't it be faster to print them by value?

[@MikeShah]

For primitive types (i.e. a 4-byte int) you're probably right. :)

[@blaisofotso3439]

Thanks Mike for answering. Looking back at the code with your answer in mind, i have just realized that no member assignment was done in the constructor with parenthesis and if i am not wrong no elements have been saved(written) to m_data. How can the u object be constructed with parenthesis in this case then?

[@MikeShah]

m_data will just be uninitialized. You should otherwise initialize it to some default value in the constructor if desired. In a few lessons I'll show how to do this with a delegate constructor. 😉

[@blaisofotso3439]

I am eager to know how it's done . Thank you ever so much

[@sallaklamhayyen9876]

great teacher + valuable content = thank you so much

[@MikeShah]

Cheers! Thank you for the kind words!

[@TheOldRoots]

Do the curly braces only prevent narrowing, or any type conversion ? Like I understand why "int a{1.4}" would give an error since you are losing information in the conversion, but would float a{3} also give an error?

[@MikeShah]

The braces require type to match, so would need to do a{3.0f}; for instance.

[@quoctrieu2413]

Thank you very much !!! Thanks to your video i found the solution to assigne values to the obj of array (myseft-defined datatype) in this way: array obj = {val1, val2, ...}

[@MikeShah]

You are most welcome!

[@joebosah2727]

Can’t get enough Carry on regardless Merci beaucoup

[@MikeShah]

Derien mon ami! Cheers!

[@brajrajsingh1001]

can anyone comment about the original souce code of various standard classes in c++ like class vector, class string , etc

[@MikeShah]

They're certainly interesting to look at and learn some tricks from -- and over time they're very useful to study more to understand exactly how things work. The STL's goal is to be portable, performant, and generic, so that may impact readability of the code however :)

[@blaisofotso3439]

Hallo Mike, why cant we print our data when we use parentheses? @12:39 / 15:52

[@MikeShah]

Parenthesis use the constructor ;) So m_data does not have any elements to print out.

[@manuvaad]

Thank you so much. Your lessons and talks are awesome as always!

[@MikeShah]

Cheers, thank you for the kind words!

[@reptilicusrex4748]

Great explanation. Thanks.

[@MikeShah]

Cheers!

[@7denis71]

Awesome! Your video lessons are awesome! :) Thank you for your doing this!

[@MikeShah]

Thank you for the kind words!

[@dolphin2954]

Great video. Thanks.

[@MikeShah]

Cheers!

[@ThislsYusuf]

I got a stack-use-after-scope on address error when using AddressSanitizer. Is this a compiler bug? (It runs well without fsanitize) Thanks for the instruction!

[@MikeShah]

Hard to know without seeing the code, do you have a timestamp in the video?

[@ThislsYusuf]

​@@MikeShah Thanks for the reply, it s the code I have after finishing the video. Hope pasting the code here isn't too cumbersome #include #include struct UDT{ UDT(std::initializer_list data) : m_data(data) { std::cout

[@MikeShah]

@@ThislsYusuf Works fine for me on g++ and clang++, perhaps a compiler bug if you're on msvc? Try pasting in compilerexplorer.com and see if it works for some other compilers.

[@ThislsYusuf]

@@MikeShah On it. Thanks!

[@hani_yt678]

Thank you for the video , keep it up !

[@MikeShah]

Absolutely!

[@rango1049]

thanks Mike

[@MikeShah]

Cheers!

[@meganfoxyou]

Very helpful, thank you!

[@MikeShah]

Cheers!

[@SuperCoolHandle94]

Thanks alot

[@MikeShah]

You're most welcome!