its probably because per contract std::array has to behave exactly like C array for legacy ops. Also this is not zero cost abstraction, so programmer has a choice: ultimate performance or extra safety.

While a bummer, most C++ compilers do have a build flag to enable bounds check in operator[]().

Which most sane compilers will do for you in debug builds.

* = [] and friends can be overloaded in C++. So just about any kind of data structure can masquerade as items[3] or *value.

Opinions differ on whether this is the great strength or fatal flaw in C++.

> "By default" means the most natural and common way to index an array, namely the [] syntax.

Sorry, I challenge your authority to decide what is "most natural way".