[all-commits] [llvm/llvm-project] fdedf3: PR44723: Trigger return type deduction for operato...

[Richard Smith via All-commits]

  Branch: refs/heads/release/10.x
  Home:   https://github.com/llvm/llvm-project
  Commit: fdedf39c46f526afb1c07b0ca91a7c5bc1e43b8f
      https://github.com/llvm/llvm-project/commit/fdedf39c46f526afb1c07b0ca91a7c5bc1e43b8f
  Author: Richard Smith <richard at metafoo.co.uk>
  Date:   2020-01-31 (Fri, 31 Jan 2020)

  Changed paths:
    M clang/include/clang/Basic/DiagnosticSemaKinds.td
    M clang/lib/Sema/SemaDeclCXX.cpp
    M clang/test/CXX/class/class.compare/class.spaceship/p2.cpp

  Log Message:
  -----------
  PR44723: Trigger return type deduction for operator<=>s whose return
types are needed to compute the return type of a defaulted operator<=>.

This raises the question of what to do if return type deduction fails.
The standard doesn't say, and implementations vary, so for now reject
that case eagerly to keep our options open.

(cherry picked from commit 42d4a55f227a1cc78ab8071062d869abe88655d9)