[libcxx-commits] [PATCH] D63053: Add nullptr output operator overload (2221)

[Marshall Clow via Phabricator via libcxx-commits]

mclow.lists added inline comments.


================
Comment at: include/ostream:717
+{
+    return *this << static_cast<const void*>(0x0);
+}
----------------
EricWF wrote:
> `static_cast<const void*>(nullptr)`;
> 
> But I'm not sure we want to forward to the `const void*` overload. My understanding of that overload is that it exists to print "bool" values for types like `ostream` that used to implement `if (stream)` via a conversion to `void*`. 
> 
> I think we may just want to print `nill`.
I suggested this approach to Zoe, because I thought that that was what GCC did. (print `0x0`)
Turns out that I was wrong; GCC prints `nullptr` (at least that's what wandbox claims about gcc 9).




================
Comment at: test/std/input.output/iostream.format/output.streams/ostream.formatted/ostream.inserters/streambuf.pass.cpp:74
+        os << nullptr;
+        assert(sb.str().c_str()[0] == '0');
+    }
----------------
EricWF wrote:
> I don't think this test is portable. Implementations can print `null` or `nill` or "hubbabalo" for that matter.
> We should probably just make this a `LIBCPP_ASSERT`. And maybe we should also assert the string isn't empty (for when other STL's use our test suite).
Agreed.


Repository:
  rCXX libc++

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D63053/new/

https://reviews.llvm.org/D63053