Comments on: How to Flatten Out A Nested Switch Statement https://www.fluentcpp.com/2017/06/27/how-to-collapse-nested-switch-statements/ Jonathan Boccara's blog Fri, 01 Jun 2018 13:58:00 +0000 hourly 1 https://wordpress.org/?v=6.5.3 By: jft https://www.fluentcpp.com/2017/06/27/how-to-collapse-nested-switch-statements/#comment-1032 Fri, 01 Jun 2018 13:58:00 +0000 https://www.fluentcpp.com/?p=1309#comment-1032 Another way to consider is to have a lambda for each combination required and to use an associative container (eg map) to provide the association between the permitted combinations and the lambda. Consider

http://coliru.stacked-crooked.com/a/923e1eac7f99dbad

In this example, an unordered_map could be used but a hash function would need to be provided…..

Whilst this idea can be extended pretty much as needed, the mapping initialisation could become rather unwieldy and time-consuming. That is why it is marked as const static so that the initialisation only takes place the first time process() is called. Also the lambda’s are const static as well so they are only initialised once. [Anything that is marked const at the beginning of a function (and cannot be constexpr) can also usually be const static so that initialisation is done only once and not once per call].

]]> By: carlo locci https://www.fluentcpp.com/2017/06/27/how-to-collapse-nested-switch-statements/#comment-368 Tue, 27 Jun 2017 07:49:00 +0000 https://www.fluentcpp.com/?p=1309#comment-368 Very interesting, thanks for sharing…

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