Why does enum declaration accept short but not Int16

Question

I want to declare a new enum with non-default underlying type. This works:

public enum MyEnum : short
{ A, B, C, }

But I don't understand the reason why this doesn't compile:

public enum MyEnum : System.Int16
{ A, B, C, }

Compiler says

Type byte, sbyte, short, ushort, int, uint, long, or ulong expected

I understand that short is an alias for Int16 on all .NET versions (32/64 bit flavors included). I don't see why the compiler gives a different meaning to the alias in that particular case.

Any explanation?

I found two almost identical questions using Google: http://stackoverflow.com/questions/3774650/enum-members-of-int32-type and http://stackoverflow.com/questions/1813408/c-int-int32-and-enums. — Daniel Daranas, Jun 01 '11 at 10:00
I didn't find it despite several minutes spent on reading search results :) — Johann Blais, Jun 01 '11 at 10:00
@Daniel Daranas, sorry I searched using int16 as a keyword... it might explain why I didn't find them — Johann Blais, Jun 01 '11 at 10:02
@Johann Blais, my search was this: http://www.google.com/search?q=c%23+enum+type+declaration+int16&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:ca:official&client=firefox-a#sclient=psy&hl=en&client=firefox-a&hs=dl3&rls=org.mozilla:ca%3Aofficial&source=hp&q=c%23+enum+type+declaration+int16+site:stackoverflow.com&aq=f&aqi=&aql=&oq=&pbx=1&fp=1&biw=784&bih=532&bav=on.2,or.r_gc.r_pw.&cad=b — Daniel Daranas, Jun 01 '11 at 10:08
@Daniel Daranas: unfortunately, this search now leads first to this question ;) — Johann Blais, Jun 01 '11 at 11:25

score 21 · Accepted Answer · edited Jan 04 '18 at 13:50

21

The syntax is correct. C# specification explicitly states that the enum's underlying type must be byte, sbyte, short, ushort, int, uint, long or ulong.

Read what Microsoft says about this here.

edited Jan 04 '18 at 13:50

Lars Gyrup Brink Nielsen

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answered Jun 01 '11 at 09:54

Daniel Daranas

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The link is broken. Please fix – Dmitry Efimenko Apr 26 '13 at 17:36
1

@Dmitry the link was killed by Microsoft - it worked when I posted it. I fixed it now, but if won't be fixing it every time it breaks. – Daniel Daranas Apr 28 '13 at 11:59

score 4 · Answer 2 · edited Jun 01 '11 at 10:17

4

"...The second example is trying to inherit from a type that derives from System.ValueType, which is strictly prohibited..."

Read here:

edited Jun 01 '11 at 10:17

Anil

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answered Jun 01 '11 at 09:54

danyolgiax

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Lot of discussion for what looks like a small thing :) – Gishu Jun 01 '11 at 09:59

Why does enum declaration accept short but not Int16

2 Answers2

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