constexpr everything?!
summary
Claim: C++ is shifting from “some constexpr” to “constexpr everything,” driven by compiler interpreters that perform symbolic execution. Clang’s constant evaluator lives in constant.cpp ~17,000 lines and uses an APValue symbolic representation with pointer provenance, versions and allocation keys. Example: a helper calculate_size runs once at parse time while prepare_storage runs twice at runtime; std containers become largely constexpr by C++26, but raw byte-reinterpret casts and some object-layout tricks still block full evaluation.
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chapters (7)
- 0:00Introduction
- 7:55What constexpr means
- 13:13Compiler evaluation of constexpr
- 20:20Pointer provenance in constexpr
- 27:12Standard containers as constexpr
- 33:20Modern constexpr features and limits
- 35:50Future of constexpr
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