alt Hacker NewsThere is in c++, too (std::ignore). Not sure why the author decided to go with the ancient void cast
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std::ignore's behavior outside of use with std::tie is not specified in any finalized standard.
https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2023/p29... aims to address that, but that won't be included until C++26 (which also includes _ as a sibling commenter mentions).
I believe C++26 now allows _ as a placeholder name [0]:
> We propose that when_ is used as the identifier for the declaration of a variable, non static class member variable, lambda capture or structured binding. the introduced name is implicitly given the [[maybe_unused]] attribute.
> In contexts where the grammar expects a pattern matching pattern,_ represents the wildcard pattern.
Some of the finer details (e.g., effect on lifetime and whether a _ variable can be used) differ, though.
https://quuxplusone.github.io/blog/2022/10/16/prefer-core-ov... does not (yet) include this as one of its examples, but it could (and someday might).