In DXC HLSL is a set of feature extensions on top of a subset of C++98. C++98 is now over 20 years old and most modern C++ users have adopted newer language constructs. This proposal suggests taking the small step of updating HLSL 202y’s base C++ language to C++11.
C++11 is over a decade old and introduced widely adopted features, many of which have been frequently requested additions for HLSL.
Adopt a C++11 base language and include the following C++11 features in HLSL 202y:
We could instead adopt an even more recent C++, like C++20. The main drawback of that is that it significantly increases the rapid divergence from DXC, and it gives us a longer list of features that we need to rectify against HLSL’s language features. Adopting a C++11 base for 202y does not prevent later versions from adopting newer C++ base standards, but it does allow us to phase the changes in iteratively as HLSL evolves.
While the original Clang 3.7 release did support C++11 fully, the intrusive changes to support HLSL broke many of the basic features Clang uses for configuring language features and supporting language modes. To restore those parts of clang sufficiently to support a C++11 base in DXC would be non-trivial. For that reason this is proposed as a Clang-only HLSL 202y feature.