How to check if enum value is valid?

Question

I am reading an enum value from a binary file and would like to check if the value is really part of the enum values. How can I do it?

Answer 1

Kinda necro, but ... makes a RANGE check of int into first/last enum values (can be combined with janm's idea to make exact checks), C++11:

Header:

namespace chkenum
{
    template 
    struct RangeCheck
    {
    private:
        typedef typename std::underlying_type::type val_t;
    public:
        static
        typename std::enable_if::value, bool>::type
        inrange(val_t value)
        {
            return value >= static_cast(begin) && value <= static_cast(end);
        }
    };

    template
    struct EnumCheck;
}

#define DECLARE_ENUM_CHECK(T,B,E) namespace chkenum {template<> struct EnumCheck : public RangeCheck {};}

template
inline
typename std::enable_if::value, bool>::type
testEnumRange(int val)
{
    return chkenum::EnumCheck::inrange(val);
}

Enum declaration:

enum MinMaxType
{
     Max = 0x800, Min, Equal
};
DECLARE_ENUM_CHECK(MinMaxType, MinMaxType::Max, MinMaxType::Equal);

Usage:

bool r = testEnumRange(i);

Mainly difference of above proposed it that test function is dependent on enum type itself only.