Like, no wonder C++ codebases are so bug-ridden, given all APIs in the
standard library are weird like this, requiring the user to completely
understand their inner workings in order to be able to use them safely.
A fix for this got made in 390d3fc06f
(2022) already, but somehow the corresponding tests were living in a
half-done stash ever since. I should probably also just do my own binary
search thing so I don't need to test everything so extensively.