The second doc has a year in the title, so it's ancient af.
The first one has multiple `C++0x` red marks (whatever that mean, afair that's how C++11 was named before standardization). It mentions `constexpr`, but doesn't know `consteval`, for example. And doesn't even mention any of C++11 attributes, such as [[noreturn]], so despite the "Last updated: 10-Aug-2021", it's likely pre-C++11 and is also ancient af and have no use in a real world.
- Hyperlinked C++ BNF Grammar (https://alx71hub.github.io/hcb/)
- EBNF Syntax: C++ (ISO/IEC 14882:1998(E)) https://www.externsoft.ch/download/cpp-iso.html
The second doc has a year in the title, so it's ancient af. The first one has multiple `C++0x` red marks (whatever that mean, afair that's how C++11 was named before standardization). It mentions `constexpr`, but doesn't know `consteval`, for example. And doesn't even mention any of C++11 attributes, such as [[noreturn]], so despite the "Last updated: 10-Aug-2021", it's likely pre-C++11 and is also ancient af and have no use in a real world.
Who might have thought. /s