"version" private word

[Dr. Assembly]

On Tuesday, 31 October 2017 at 13:53:54 UTC, Jacob Carlborg wrote:
> On 2017-10-31 14:46, Igor Shirkalin wrote:
>> Hello!
>> 
>> We need some conditional compilation using 'version'.
>> Say we have some code to be compiled for X86 and X86_64.
>> How can we do that using predefined (or other) versions?
>> Examples:
>> 
>>     version(X86 || X86_64) // failed
>>     version(X86) || version(X86_64) // failed
>> 
>> 
>> The following works but it is too verbose:
>> 
>> version(X86) {
>>      version = X86_or_64;
>> }
>> version(X86_64) {
>>      version = X86_or_64;
>> }
>
> The only alternative is to do something like this:
>
> version (X86)
>     enum x86 = true;
> else
>     enum x86 = false;
>
> else version (X86_64)
>     enum x86_64 = true;
> else
>     enum x86_64 = false;
>
> static if (x86 || x86_64) {}

Why is that keyword called enum? is this any related to the fact 
enumeration's field are const values? it would be called 
invariable or something?