Understanding enum ranges and C++ type behavior
This is a medium-difficulty C++ language-knowledge question that tests your grasp of how enums work under the hood, particularly around their underlying integral type, range semantics, and the rules governing type conversions and comparisons. It rewards careful reading of the code and familiarity with C++ standard semantics rather than guesswork.
To approach problems like this, you need to understand what integral type an enum uses by default, how enums relate to their underlying values, and what happens when you attempt operations that push against the boundaries of those types. The question often hinges on subtle details: whether a particular operation is well-defined, undefined, or simply produces a surprising result.
- Enum underlying types and default sizing
- Implicit and explicit type conversions involving enums
- Defined vs. undefined behavior in enum range operations
- How compilers handle enum-to-integral comparisons and assignments