[PATCH] D46845: [libcxx][c++17] P0083R5: Splicing Maps and Sets

[Richard Smith - zygoloid via Phabricator via cfe-commits]

rsmith added a comment.

In https://reviews.llvm.org/D46845#1105638, @erik.pilkington wrote:

> make __map_node_handle use a const_cast on the key instead of type-punning between pair<const K, V> and pair<K, V>. Add calls to std::launder in key() and before inserting a node handle.


Can you do this as a separate change, prior to adding node_handle? I would in particular expect this to result in the removal of the `union __value_type` from <map>.


https://reviews.llvm.org/D46845