Custom enum literals in C++

23 Oct 2023

EnumLiterals

Enums in C++ are a convenient way to define a set of named values. However, the default behavior of enums is to assign integer values to the named constants in sequential order. This default behavior can sometimes be limiting, especially when you want to use more meaningful or custom literals for your enum constants.

In this blog post, we will explore how to create custom enum literals in C++. This feature allows you to explicitly define the values for enum constants, providing more flexibility and readability to your code.

Enum Basics

Let’s start with a basic example of an enum:

enum Color {
    RED,
    GREEN,
    BLUE
};

In this case, the enum constants RED, GREEN, and BLUE will be automatically assigned values of 0, 1, and 2, respectively.

Custom Enum Literal Syntax

To define custom literals for enum constants, we can use the following syntax:

enum class Color {
    RED = 5,
    GREEN = 10,
    BLUE = 20
};

In this modified example, we have explicitly assigned the values 5, 10, and 20 to the enum constants RED, GREEN, and BLUE.

Benefits of Custom Enum Literals

Improved Clarity: By providing custom literals, you can make your code more self-explanatory. Instead of relying on arbitrary integer values, you can use meaningful names that directly reflect the intended purpose of each enum constant.
Flexibility: Custom enum literals give you more control over the values assigned to each constant. This can be useful when you need to synchronize your enum values with external sources or when you want to maintain consistency across different parts of your codebase.

Usage Examples

The following examples demonstrate how custom enum literals can be used in practice:

enum class Day {
    MONDAY = 1,
    TUESDAY,
    WEDNESDAY,
    THURSDAY,
    FRIDAY,
    SATURDAY,
    SUNDAY
};

Day today = Day::WEDNESDAY;

In this example, the enum constant TUESDAY will automatically be assigned the value 2, and each subsequent constant will be assigned an incrementing value.

Conclusion

Custom enum literals provide a powerful way to assign specific values to enum constants in C++. This feature enhances code readability and provides more control over the values assigned to each constant. By using meaningful literals, you can make your code more expressive and self-explanatory.

With custom enum literals, you can overcome the limitations of the default enum behavior and create more robust and maintainable code.

Give custom enum literals a try in your next C++ project, and enjoy the benefits of improved clarity and flexibility!

References:

#C++ #EnumLiterals