[libcxx-commits] [PATCH] D117332: [libc++] Make sure basic_string::reserve never shrinks in all standard modes

[Louis Dionne via Phabricator via libcxx-commits]

ldionne added a comment.

I am reconsidering my decision now. Let's put ourselves in the shoes of a programmer that wrote code in C++03 when the standard did say "if n < size(), this is a non-binding shrink-to-fit request". They most likely used `str.reserve()` with the exact expectation that it was going to `shrink_to_fit`.

API consistency is relevant for new code being written, however new code being written won't use `reserve()` because it's deprecated. So my opinion is now that if we change `reserve()` to never shrink, we're making the wrong tradeoff - existing code may change performance characteristics, and new code won't benefit from the consistency because new code won't use `reserve()` anyways.

Thoughts? If you agree, I'll turn this patch around and make `reserve(n)` never shrink in all standard modes, but I won't touch `reserve()` (so that it shrinks to fit in all standard modes).


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D117332/new/

https://reviews.llvm.org/D117332