Support for passing C++ templates as arguments to template template parameters. #6475
Conversation
zygoloid
changed the title
chandlerc
left a comment
chandlerc
left a comment
There was a problem hiding this comment.
Minor comment suggesting a potential place we might want another TODO, but nothing substantive and optional if it doesn't actually make sense.
Super nice change overall!
toolchain/check/cpp/call.cpp
Outdated
| // Synthesize a placeholder `void{}` template argument, that will never be a | ||
| // valid argument for any template parameter. This is used in order to get Clang | ||
| // to diagnose invalid template argument errors for us. |
There was a problem hiding this comment.
Maybe add that this will map this void{} argument's source location to the Carbon argument's source location?
It's a bit of an implementation detail, but key to making the diagnostic effective.
Also, would it make sense to flag this as a candidate for an extension point in Clang so that even when the void{} is printed within the diagnostic text it can either call back into Carbon to print the expression or at least say something like <Carbon placeholder expression> instead of void{}? If so, maybe a TODO? Not looking to do more than the current code does in this PR, just to record that we could go further here.
zygoloid
force-pushed
the
toolchain-interop-template-template-args
branch
from
b18013e to
5fcfccf
Compare
2 participants
Allow passing a C++ template as a template template argument to another C++ template. Does not allow passing a Carbon generic as an argument.
Depends on #6474.