I'm the author of the <latch> PR for Core so I'm also naturally in favor of this addition. What's the protocol for accepting such a library into Boost? Does it still go through formal review? Most of what would go in there exists in already-accepted Boost libraries. For example, the aforementioned Boost.Algorithm and Boost.Core contains several such things as <span>, <bit> and in its detail folder, <string_view>. The good news though is that because we're simply polyfilling standardized practice, there's no need to bikeshed interfaces. Oh, I almost forgot about Boost.Optional. How do we reify all of these existing classes and functions? - Christian