The C++ Standard Library Has Been Walking Itself Back for Fifteen Years

# Summary The C++ Standard Library has systematically deprecated and removed features for fifteen years after initially shipping them, starting with std::function in C++11, which the committee now recommends avoiding in new code. The article catalogs three tiers of these "walk-backs": formally deprecated features (like std::auto_ptr and std::random_shuffle), informally avoided features that the community knows to skip, and unfixable standard library containers that remain problematic due to ABI compatibility constraints. This pattern reflects fundamental design mistakes that the committee acknowledges through deprecations and replacements, yet cannot always remedy without breaking existing code.