[all-commits] [llvm/llvm-project] 38774c: [ADT] Avoid needless iterator copies in `zippy`

[Jakub Kuderski via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 38774c4f39a78deab1dd35ff45bc557300cd9b29
      https://github.com/llvm/llvm-project/commit/38774c4f39a78deab1dd35ff45bc557300cd9b29
  Author: Jakub Kuderski <kubak at google.com>
  Date:   2023-03-06 (Mon, 06 Mar 2023)

  Changed paths:
    M llvm/include/llvm/ADT/STLExtras.h
    M llvm/unittests/ADT/IteratorTest.cpp

  Log Message:
  -----------
  [ADT] Avoid needless iterator copies in `zippy`

Make `zip_common` increment and decrement iterators in place.

This improves performance with iterator types that have non-triviall
copy constructors.

Reviewed By: zero9178

Differential Revision: https://reviews.llvm.org/D145337