Comments on: When to Use Enums and When to Use Tag Dispatching in C++ https://www.fluentcpp.com/2018/05/01/when-to-use-enums-and-when-to-use-tag-dispatching-in-cpp/ Jonathan Boccara's blog Sun, 07 Oct 2018 13:59:00 +0000 hourly 1 https://wordpress.org/?v=6.5.3 By: Jonathan Boccara https://www.fluentcpp.com/2018/05/01/when-to-use-enums-and-when-to-use-tag-dispatching-in-cpp/#comment-1367 Sun, 07 Oct 2018 13:59:00 +0000 https://www.fluentcpp.com/?p=1797#comment-1367 In reply to Kilian.

I think this is interesting, and would love to see that idea developed into a code snippet to see how it would look like in client code interface and implementation.

]]> By: Kilian https://www.fluentcpp.com/2018/05/01/when-to-use-enums-and-when-to-use-tag-dispatching-in-cpp/#comment-1334 Thu, 27 Sep 2018 13:46:00 +0000 https://www.fluentcpp.com/?p=1797#comment-1334 What do you think about using a variant ? By using a variant I ensure the type-safety, i.e. the user is only allowed to pass valid values and I have the possibility to make the resolution/dispatching at run-time. The disadvantage is probably the implementation of the function. Dispatching on a variant might be harder than on an enum or using tag-dispatching.

]]> By: Jonathan Boccara https://www.fluentcpp.com/2018/05/01/when-to-use-enums-and-when-to-use-tag-dispatching-in-cpp/#comment-959 Thu, 03 May 2018 23:18:00 +0000 https://www.fluentcpp.com/?p=1797#comment-959 In reply to Sean D. Cline.

Yes, great points, thanks for sharing!

]]> By: Jonathan Boccara https://www.fluentcpp.com/2018/05/01/when-to-use-enums-and-when-to-use-tag-dispatching-in-cpp/#comment-960 Thu, 03 May 2018 23:18:00 +0000 https://www.fluentcpp.com/?p=1797#comment-960 In reply to Johann Gerell.

Fixed, thanks!

]]> By: Sebastien Dicaire https://www.fluentcpp.com/2018/05/01/when-to-use-enums-and-when-to-use-tag-dispatching-in-cpp/#comment-958 Thu, 03 May 2018 14:35:00 +0000 https://www.fluentcpp.com/?p=1797#comment-958 In reply to CarelC.

throw std::invalid_argument(“Oi mate, what u doin?”);

]]> By: Johann Gerell https://www.fluentcpp.com/2018/05/01/when-to-use-enums-and-when-to-use-tag-dispatching-in-cpp/#comment-957 Thu, 03 May 2018 08:10:00 +0000 https://www.fluentcpp.com/?p=1797#comment-957 The Related Articles bullet point isn’t a link…

]]> By: Staffan Tjernstrom https://www.fluentcpp.com/2018/05/01/when-to-use-enums-and-when-to-use-tag-dispatching-in-cpp/#comment-956 Wed, 02 May 2018 12:40:00 +0000 https://www.fluentcpp.com/?p=1797#comment-956 With C++17 you can have your cake and eat it, if you go for the if constexpr solution. Now you can get the cache / locality benefits of the enum solution with the compile time benefits as well, without the type universe pollution that tag dispatching introduces.

]]> By: Sean D. Cline https://www.fluentcpp.com/2018/05/01/when-to-use-enums-and-when-to-use-tag-dispatching-in-cpp/#comment-955 Wed, 02 May 2018 11:42:00 +0000 https://www.fluentcpp.com/?p=1797#comment-955 Articles comparing the different ways to do something are always fun. Here’s another way to think about:
https://godbolt.org/g/w8pNiW
(Using an enum as a template argument to achieve a form of tag dispatching.)

]]> By: Jonathan Boccara https://www.fluentcpp.com/2018/05/01/when-to-use-enums-and-when-to-use-tag-dispatching-in-cpp/#comment-954 Wed, 02 May 2018 07:06:00 +0000 https://www.fluentcpp.com/?p=1797#comment-954 In reply to CarelC.

Yes, good point thanks!

]]> By: CarelC https://www.fluentcpp.com/2018/05/01/when-to-use-enums-and-when-to-use-tag-dispatching-in-cpp/#comment-953 Wed, 02 May 2018 06:48:00 +0000 https://www.fluentcpp.com/?p=1797#comment-953 Nice article.
I think it might be worth mentioning that with the enum you need to handle out of range values and with the tag dispatch this is not needed since you can not get an invalid/undefined tag to compile.
For example on the enum example calling writeToFile(“myFile.txt”, “contents”, static_cast(10));

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