• Shriramana Sharma (11/11) Dec 14 2015 Hello. I was trying to do something like this:
• Kagamin (2/2) Dec 14 2015 They are promoted to int in arithmetic operations unless compiler
• Adam D. Ruppe (11/12) Dec 14 2015 That's not an integer literal... that's a runtime value of ubyte
• Shriramana Sharma (4/5) Dec 14 2015 Thanks for that explanation. That's clear now.

Shriramana Sharma <samjnaa_dont_spam_me gmail.com> writes:

Hello. I was trying to do something like this:

ubyte code = to!ubyte(spec, 6) + 16;

and got an error saying:

cannot implicitly convert expression (cast(int)to(spec, 6) + 16) of type int 
to ubyte

Looking at http://dlang.org/spec/lex.html#IntegerLiteral, sure enough 16 is 
specified to be inferred as an `int`.

I thought that integer literals used to be inferred as the smallest integral 
type that can fit them – am I mistaken?

-- 

Kagamin <spam here.lot> writes:

They are promoted to int in arithmetic operations unless compiler 
can prove the value doesn't exceed its range.

Adam D. Ruppe <destructionator gmail.com> writes:

On Monday, 14 December 2015 at 13:33:41 UTC, Shriramana Sharma 
wrote:
 ubyte code = to!ubyte(spec, 6) + 16;

That's not an integer literal... that's a runtime value of ubyte 
plus an integer literal.

Since the ubyte is the result of a runtime function, the compiler 
doesn't know what it will be and thinks it could be anything from 
0 to 255, inclusive.

240 + 16 = 256 = too big to fit in a ubyte, to it requires a cast.

ubyte code = 16; // this would work

ubyte code = 239 + 16; // this too

but yours won't because to!ubyte(spec, 6) might just be > 240.

Shriramana Sharma <samjnaa_dont_spam_me gmail.com> writes:

Adam D.  Ruppe wrote:
 but yours won't because to!ubyte(spec, 6) might just be > 240.

Thanks for that explanation. That's clear now.

--