On Thu, 01 Oct 2009 10:16:08 -0400, Jeremie Pelletier wrote: > Saaa wrote: >> I think is very bug-prone, isn't it obvious iub should be -5? >> >> ubyte ub = 5; >> int iub = -ub; // iub now is 251 >> >> What is the reasoning to do it this way? > > Minus toggles the most significant bit, be it on a signed or unsigned > type. When converting it to an int, the byte being signed or unsigned > does make a difference: when unsigned the number is copied as is, when > signed the most significant bit (bit 7) is shifted to the most > significant bit of the int (bit 31). > > Its therefore pretty standard logic, no warning is given since the > entire ubyte range fits within an int > > Jeremie
This is a troublesome behavior: ubyte z = 5; int x = -z; // x now is 251 int y = -1 * z; // y is now -5
