can't print volatile void*

[ZXShady]

this is the same issue with std::ostream operator that will be fixed in C++23

godbolt

[Dani-Hub]

What the submitter is referring to is the adopted paper P1147.

[vitaut]

Since {fmt} disallows arbitrary pointers you still need a cast in which case volatile can be omitted. Is there a more compelling example?

[Dani-Hub]

Since {fmt} disallows arbitrary pointers you still need a cast in which case volatile can be omitted. Is there a more compelling example?

I think a more compelling example is that you have actually a volatile T* p for formatting, but it doesn't suffice to add apply static_cast<const void*> to p in your code, but you also need to add another const_cast<const T*> to it first.

[ZXShady]

@vitaut

lets say I have a volatile int* and want to format it I have to do this

volatile int* p = (int*)0xdeadbeef;
fmt::format("{}",const_cast<void*>(static_cast<volatile void*>(p))); // or do static_cast<void*>(const_cast<int*>(p))

if fmt allowed to print const volatile void* then I do not need the last const cast.

the godbolt link was to show that you can't print it

[vitaut]

Makes sense, a PR to avoid volatile void* support would be welcome.