shafik added a comment. In D133029#3763688 <https://reviews.llvm.org/D133029#3763688>, @ilya-biryukov wrote:
> In D133029#3763120 <https://reviews.llvm.org/D133029#3763120>, @shafik wrote: > >> Do you have an idea of how common this might be? > > I don't have the numbers yet, but this broke the builds in C++20 mode inside > the core libraries we are using after libc++ change > <https://github.com/llvm/llvm-project/commit/98d3d5b5da66e3cf7807c23a0294280bb796466b> > that makes vector `constexpr`. > I suspect every medium-to-large codebase will have a few instances. > One common pattern that I have seen goes something like: > > // foo.h > struct Inner; > class Outer { > std::vector<Inner> elements; > private: > size_t size() { return elements.size(); } > void some_other_method(); > }; > > struct Inner { > Outer* outer; > }; > > // foo.cpp > Outer::some_other_method() { /* uses members that would actually fail with > incomplete type */ } This old cfe-dev thread might be relevant: https://lists.llvm.org/pipermail/cfe-dev/2018-June/058338.html It appears that folks take advantage of this working a lot. It sounds like your saying w/ constexpr std::vector this would be ill-formed in a constant expression context now. Which won't effect most of the existing code I think? Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D133029/new/ https://reviews.llvm.org/D133029 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
