On 6 February 2018 at 19:27, Peter T. Breuer <ptb@xxxxxxxxxxxxxx> wrote: > "Also sprach Jonathan Wakely:" >> >> See the C standard. >> > >> > Where specifically? I am now looking at the draft standard for >> > ISO-whatever at >> > >> > http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1256.pdf >> >> The specification of each operator of course! > > I am and have been looking straight at them, and I see nothing that > says that conversions should not be applied to their operators. > > >> You've been pointed to them multiple times now, 6.5.5, and 6.5.6, and >> 6.5.7, and so on. > > They contain nothing (6.5.7 is the ony one on the bitwise shift > operators; 6.5.5 is additive operators, 6.5.6 is multiplicative). We > have been quoting what 6.5.7 says here. > >> Are you trolling or just stubborn and unable to accept the help you asked for? > > I would be grateful if you desisted from ad hominen attacks. Stop acting like an idiot then. > WHAT, specifically, do you see in 6.5.7 that allows the conversion > specified by the general rule of conversions > > If one operand has an unsigned type T whose conversion rank is at least > as high as that of the other operand's type, then the other operand is > converted to type T. > > NOT to be applied? Because it doesn't say they are applied. As I pointed out in https://gcc.gnu.org/ml/gcc-help/2018-02/msg00031.html the other operators *do* say the conversions are applied. > You've been hot on claiming you have done the pointing, but light on > doing it! It should not be hard. > >> Maybe this will help: >> http://en.cppreference.com/w/c/language/conversion#Usual_arithmetic_conversions > > The arguments of the following arithmetic operators undergo implicit > conversions for the purpose of obtaining the common real type, which > is the type in which the calculation is performed: > binary arithmetic *, /, %, +, - > relational operators <, >, <=, >=, ==, != > binary bitwise arithmetic &, ^, |, > the conditional operator ?: > > That's all. No ">>" operator there, so no maybe. Your claim is false > there. Exactly, the shift operators are not listed there, because the conversions are not done for the shift operators. >> And specifically: > >> http://en.cppreference.com/w/c/language/operator_arithmetic#Shift_operators > > That's a different place ... it seems to say what we have already > quoted in the standard. > > First, integer promotions are performed, individually, on each operand > (Note: this is unlike other binary arithmetic operators, which all > perform usual arithmetic conversions). The type of the result is the > type of lhs after promotion. > > No integer promotions can be performed, since the args are already ints. Read the parenthesis! It explicitly says that for these operators, unlike most others, arithmetic conversions are not performed! > There is no "Second". > > If they meant to say > > "Second: NO sign conversions MAY be performed, so what you get after > (possibly vacuuous) int promotion you are stuck with, " > > then they forgot to say it. You are an idiot.
