[clang] [clang] check deduction consistency when partial ordering function templates (PR #100692)

[Matheus Izvekov via cfe-commits]

mizvekov wrote:

It's one thing that we might tweak the rules to account for redundant parenthesis.
But the more complete example shows there is no way to order these unrelated things.

Note that we hadn't so far implemented these rules for partial ordering of function templates, but the same issue should already exist for all implementations when you convert this example to class templates partial specializations, so the approach Eigen is taking here is not standing on solid ground.

https://github.com/llvm/llvm-project/pull/100692