Post #25751 7 Oct 4, 2026, 12:23 UTC The complement of true is true, except when it's falsehttps://dryperspective.github.io/posts/complement-of-true/https://redd.it/1wwtdsz@r_cpp Substitution Failure The complement of true is true, except when it's false Consequences of integral promotion, UB on unscoped enums, and why boolean conversion is surprising.