I think clang's noescape attribute for pointer function parameters are somewhat related. There are several compiler extensions that allow refining calling conve

I think clang's noescape attribute for pointer function parameters are somewhat related. There are several compiler extensions that allow refining calling conventions, so clearly even compiler vendors think that there are things to explore here. Having said that I think the suggestion would be observably break both the current C and C++ standards, so something like this shouldn't be done without an explicit attribute.