Moved-from Objects in C++
summary
Argues that C++’s core is uncompromising performance achieved by allowing undefined behavior, then drills into move semantics: moved-from objects are partially formed objects and should only be assigned-to or destroyed. Shows concrete costs and surprises: vector move forces zeroing size/capacity under the standard note, list with sentinel nodes can make moves throw, a viewport ID wrapper forces expensive reallocation or faked accessors, and std::sort with unique_ptr comparators exposes inconsistent guarantees. C++26 tweaks are noted; slides and examples are on the uploader’s links.
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chapters (9)
- 0:00C++ philosophy and goals
- 7:43C++ superpower: performance
- 11:43Undefined behavior in C++
- 23:04Move semantics introduction
- 27:36Problem with moved-from objects
- 35:55Restrict moved-from objects
- 48:11Proposed move semantics
- 56:38Safety vs performance
- 1:03:38Q&A
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