Re: How can I get rid of "Warning C4307: integral constant overflow"

From:
"Ben Voigt [C++ MVP]" <rbv@nospam.nospam>
Newsgroups:
microsoft.public.vc.language
Date:
Mon, 11 Jun 2007 13:05:49 -0500
Message-ID:
<OWQnGNFrHHA.4300@TK2MSFTNGP05.phx.gbl>
"_Christopher(M2M)" <m2mm4m-ng@yahoo.co.uk> wrote in message
news:s6adnbDrdPKJVfjbnZ2dnUVZ8ternZ2d@bt.com...

Microsoft Visual Studio 2005 Version 8.0.50727.762 (SP.050727-7600)

How do I get rid of "Warning C4307: '-' : integral constant overflow" from
the following macro?
   #define d_ReturnMax(I_iTypeSize)\
   ( (int64(1)<<((I_iTypeSize*8)-1))-1)


Use uint64 in previous line.

There NO warnings when done as a function:
   int64 d_ReturnMax(int64 I_iTypeSize)
   { return (1<<((I_iTypeSize*8)-1))-1;}

Test code:
   int64 L_iMaxIntSize=d_ReturnMax(sizeof(int32)); //
L_iMaxIntSize=0x000000007fffffff
   int64 L_iMaxIntSize=d_ReturnMax(sizeof(char)); //
L_iMaxIntSize=0x000000000000007f

I tried typecasting around all parts of code i.e. int64(...)/(int64)... I
give up now.
Can anyone else spot something I have missed?

--
From _Christopher (M2M).
RefCode:44CdccTCDf42 V04
void DeadEnds() {for(;;);} // :)

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