[all-commits] [llvm/llvm-project] fd66b4: [libc++] Add an assertion in the subrange construc...

[Louis Dionne via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: fd66b44ec19e76c111c8a37a42dcb4b44a96bfd6
      https://github.com/llvm/llvm-project/commit/fd66b44ec19e76c111c8a37a42dcb4b44a96bfd6
  Author: Louis Dionne <ldionne.2 at gmail.com>
  Date:   2021-09-03 (Fri, 03 Sep 2021)

  Changed paths:
    M libcxx/include/__ranges/subrange.h
    M libcxx/test/std/ranges/range.utility/range.subrange/primitives.pass.cpp
    M libcxx/test/std/ranges/range.utility/range.subrange/types.h

  Log Message:
  -----------
  [libc++] Add an assertion in the subrange constructors with a size hint

Those constructors are very easy to misuse -- one could easily think that
the size passed to the constructor is the size of the range to exhibit
from the subrange. Instead, it's a size hint and it's UB to get it wrong.
Hence, when it's cheap to compute the real size of the range, it's cheap
to make sure that the user didn't get it wrong.

Differential Revision: https://reviews.llvm.org/D108827