How to Explicitly Convert Strongly Typed Enums to Integers in C ?

Automatically Converting a Strongly Typed Enum into Integer Type

In C , strongly typed enums ensure greater type safety than traditional enums. However, unlike traditional enums, strongly typed enums cannot be implicitly converted to integer types.

To convert a strongly typed enum value E into an integer type, an explicit cast is required, such as:

<code class="cpp">int i = static_cast<int>(b::B2);</code>

However, if the underlying type of the enum is unknown, the following template function can be used:

<code class="cpp">template <typename E>
constexpr typename std::underlying_type<E>::type to_underlying(E e) noexcept {
    return static_cast<typename std::underlying_type<E>::type>(e);
}</code>

Now, the conversion can be performed without specifying the underlying type explicitly:

<code class="cpp">std::cout << foo(to_underlying(b::B2)) << std::endl;</code>

It's important to note that this conversion only works for values of strongly typed enums. If a traditional enum value is provided to to_underlying(), an error will be raised.

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