Скачать или смотреть How to Effectively Cycle Through an Enum in C+ +

Discover a straightforward method to cycle through enums in C+ + . Learn to implement a clean solution by avoiding redundancy without using dummy values!
---
This video is based on the question https://stackoverflow.com/q/68475458/ asked by the user 'Compizfox' ( https://stackoverflow.com/u/1509372/ ) and on the answer https://stackoverflow.com/a/68484328/ provided by the user 'Clifford' ( https://stackoverflow.com/u/168986/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: What is a nice way to cycle through an enum?

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
How to Effectively Cycle Through an Enum in C+ +

When developing user interfaces in embedded projects, one common task is to manage states or menu items. A frequent technique is to use enums for better organization and readability. However, cycling through these enums comes with its challenges. Below, we will explore a neat way to accomplish this without compromising code quality.

Background

Enums are a great way to define a set of named integral constants. For example, consider the following enum to represent different menu states:

[[See Video to Reveal this Text or Code Snippet]]

In this structure, you can easily set the current menu item:

[[See Video to Reveal this Text or Code Snippet]]

However, the challenge arises when you want to advance to the next menu item. As more enums are added, managing them effectively and cleanly becomes essential, particularly in the context of cycling through the enum values with button presses.

The Problem with Direct Incrementing

While it is tempting to increment the enum value directly by casting it to an integer, you quickly run into problems with boundary conditions. For instance, if you simply increment the enum like this:

[[See Video to Reveal this Text or Code Snippet]]

The above implementation lacks proper boundary checking and does not wrap around once it reaches the end of the enum definitions. Thus, as you increment, you may end up with invalid values.

A Better Approach: Sentinel Values

Instead of appending a dummy _count value at the end of your enum, we can use a more elegant approach. You can set the last enumerated value to be an actual named value:

[[See Video to Reveal this Text or Code Snippet]]

By implementing a sentinel like this, you can easily modify your increment logic to correctly wrap around without introducing invalid enum states.

Updated Increment Logic

When incrementing the value, you can modify your code to:

[[See Video to Reveal this Text or Code Snippet]]

This leverages the last enumerated value to establish a clean boundary for cycling through the enum definitions.

Flexible Function Handlers

Sometimes, rather than relying purely on enums, it may be beneficial to utilize function pointers for your menu item handlers. This can allow you to easily extend functionality in a more dynamic manner without strictly adhering to the enum structure.

For example:

[[See Video to Reveal this Text or Code Snippet]]

This way, you can easily cycle through handlers based on their index instead of juggling with enums.

Conclusion

Cycling through enums in C+ + does not have to be a cumbersome process. By setting a designated last value in your enum, you can streamline the process of cycling through states while avoiding redundancy and complications with invalid states.

Give these methods a try in your next embedded project, and experience a more manageable state handling system for your user interface!