> -----Original Message----- > From: gcc-help-owner@xxxxxxxxxxx [mailto:gcc-help-owner@xxxxxxxxxxx] On > Behalf Of Jonathan Wakely > Sent: Wednesday, September 17, 2014 11:01 AM > To: Andy Falanga (afalanga) > Cc: gcc-help@xxxxxxxxxxx > Subject: Re: Possible bug in gcc 4.4.7 > > On 17 September 2014 17:16, Andy Falanga (afalanga) wrote: > > Flag operator &=(Flag& f1, Flag f2) { > > return static_cast<Flag>(reinterpret_cast<unsigned int&>(f1) > > &= static_cast<unsigned int>(f2)); } > > That reinterpret_cast looks dodgy to me, accessing the object through a > different type is undefined behaviour. What's wrong with doing it > safely? > > Flag operator &=(Flag& f1, Flag f2) { > unsigned int i = f1; > i &= static_cast<unsigned int>(f2); > return f1 = static_cast<Flag>(i); > } Ha, nothing except my thinking that, because I was casting a reference, I had to use reinterpret_cast<>. Of course, that (your suggestion) worked for me. Please point me to the correct section of the language spec so that I might better understand why this is undefined behavior. Thanks Jonathan. Andy
