How to check if enum value is valid?

by

enum value is valid in C++ if it falls in range [A, B], which is defined by the standard rule below. So in case of enum X { A = 1, B = 3 }, the value of 2 is considered a valid enum value.

Consider 7.2/6 of standard:

For an enumeration where emin is the smallest enumerator and emax is the largest, the values of the enumeration are the values of the underlying type in the range bmin to bmax, where bmin and bmax are, respectively, the smallest and largest values of the smallest bit-field that can store emin and emax. It is possible to define an enumeration that has values not defined by any of its enumerators.

There is no retrospection in C++. One approach to take is to list enum values in an array additionally and write a wrapper that would do conversion and possibly throw an exception on failure.

See Similar Question about how to cast int to enum for further details.

More Related Contents:

  1. Referring to c++ enums [closed]
  2. c++ Making a code that displays equations and keep getting the “expression must have integral or unscoped enum type” error
  3. Is there a simple way to convert C++ enum to string?
  4. How to use enums as flags in C++?
  5. How can I iterate over an enum?
  6. How to easily map c++ enums to strings
  7. C++: Print out enum value as text
  8. Forward declaring an enum in C++
  9. Base enum class inheritance
  10. C++ string to enum
  11. Should I use #define, enum or const?
  12. Are C++ enums signed or unsigned?
  13. Enumerate over an enum in C++
  14. Allow for Range-Based For with enum classes?
  15. Is it possible to determine if a type is a scoped enumeration type?
  16. What is the underlying type of a c++ enum?
  17. Extending enums in C++?
  18. Pros and cons of using nested C++ classes and enumerations?
  19. Difference between Enum and Define Statements
  20. How to use C++11 enum class for flags
  21. Detect when multiple enum items map to same value
  22. Why do you use typedef when declaring an enum in C++?
  23. what is the size of an enum type data in C++?
  24. Equivalent of “using namespace X” for scoped enumerations?
  25. generating random enums
  26. namespaces for enum types – best practices
  27. Do C++ enums Start at 0?
  28. Why must an enumeration’s size be provided when it is forward declared?
  29. Signedness of enum in C/C99/C++/C++x/GNU C/GNU C99
  30. How can I extend a lexical cast to support enumerated types?

Leave a Comment