[PATCH] D26373: [analyzer] Provide Contains() on ImmutableMap program state partial trait.

[Dominic Chen via cfe-commits]

ddcc added a comment.

Even though there isn't a performance difference, I think it is semantically clearer since it is explicit that the value is unneeded.

The interface of ProgramState provides a `contains()` function that calls into `Contains()` of the underlying partial traits as part of its implementation. That function is present for `ImmutableSet` and `ImmutableList`, so it is inconsistent that `ImmutableMap` doesn't have it. I've been working on a Z3 constraint backend that uses this, though the implementation has been trickier than I expected.


https://reviews.llvm.org/D26373