C++: So close, and yet so far away?

"Here, we will only briefly mention other ways of breaking the C++ type system. These problems are well known and have well-known solutions, so we will not address them here. Misuse of unions and casts can lead to type and memory violations (so follow the rules that prevent that [Stroustrup,2015]). For example, use a variant class rather than a plain union. Out-of-range access and access through a null pointer can lead to type and memory errors (so follow the rules that prevent that). In particular, use array_view and not_null from the Guideline Support Library (GSL) [Sutter, 2015b]. To minimize range errors, we also recommend using a make_array() function that returns an owner> to allocate an array on the free store, rather than using new or malloc() directly. The aim of the Code Guidelines is to eliminate a large range of errors by mutually supportive rules. No one rule can by itself prevent a large class of errors: ban one misuse and others will become popular (this is often referred to as “playing whack-a-mole”). Thus, our ideal is a large set of mutually supportive rules that together deliver type and memory safety guarantees."