Created attachment 50443 [details]
Temp file for provided source
The following program is valid in all versions of GCC from 4.7.1 through trunk. Relational operations on std::nullptr_t don't really make sense since there's only one value.
auto lt = nullptr < nullptr;
auto gt = nullptr > nullptr;
auto le = nullptr <= nullptr;
auto ge = nullptr >= nullptr;
This was apparently addressed by DR583/N3478 (thanks to Richard Smith for providing these).
* All GCC releases at least as far back as 4.7.1 (where I stopped looking).
# System type
* Debian (checked GCC 10.2.1)
* Compiler Explorer (checked all other reported versions).
# Options given to GCC
`g++ -save-temps nullptr-relop.cpp -c -std=c++20`
Mine (for GCC 12).
Fixed in GCC 12.