The C++ Standard Library Has Been Walking Itself Back for Fifteen Years
The C++ Standard Library has been undergoing significant changes over the past fifteen years, with many features being deprecated or replaced. A recent post highlights the legacy status of std::function and the introduction of std::copyable_function in C++26. This trend of walking back features has been consistent, with the committee acknowledging design errors and encouraging developers to avoid outdated components.
- ▪The C++ committee has been deprecating features since C++11, advising against the use of legacy components.
- ▪std::function, introduced in C++11, is now labeled as legacy and should be avoided in new code.
- ▪The introduction of std::copyable_function in C++26 represents the latest effort to replace outdated library features.
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The C++ Standard Library Has Been Walking Itself Back for Fifteen Years, and the Receipts Are Public Published: May 23, 2026 The C++ standard library has been walking itself back for fifteen years, and the receipts are public Sandor Dargo's post this month on std::copyable_function closes with a quick-reference table. Four callable wrappers, one recommendation each, and at the bottom of the list one entry that should stop any working C++ engineer cold: std::function: Legacy. Avoid in new code. std::function shipped in C++11. The committee spent fifteen years shipping the wrappers that should replace it. The latest, std::copyable_function, lands in C++26.
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Excerpt limited to ~120 words for fair-use compliance. The full article is at HFT University.