The C++ community is talking about evolving in the following ways in this space:
1. contracts
2. profiles
3. successor languages
4. borrow checking
The idea of a "subset of the language" is one that's often talked about, but there seems to be an explicit rejection of the idea of a subset, at least by several important committee members. It's not clear to me why this is the case.
I’m not sure why you’re getting downvoted. The committee members have clear interest to keep things as they are. However, from a practical perspective I suspect that “subset lang” will happen. One just needs a linter or compiler flags to do that.
The thing is, there's a difference between a true subset and "some flags that reject certain things." Because that creates a number of different sets that may relate to each other in a variety of ways, some subsets, some overlapping.
But beyond the specific definitions here, "profiles" is that sort of approach, so something like it will happen, probably. It seems to have a lot of support.
"Subset language" is already an option. The developer can choose a safe(r) subset of C++ to constrain themselves to. Many (most?) C++ shops already do this, and go to varying lengths to enforce that only their blessed subset is used. We don't really need a committee to create a new "subset language" to accomplish this.
