string_view is a new feature designed on purpose to be unsafe.

The idea was to copy slices model from memory safe languages, naturally being C++ with C's influence regarding performance trumps safety, string_view couldn't be made to be as safe as the idea they were copying from.

Another example is span, while C#'s Span and Microsoft's gsl::span do bounds checking, ISO C++17 span naturally leaves it to the developer's responsibility.

> The idea was to copy slices model from memory safe languages

No, the idea was to make a simple one-to-one wrapper for the "char, char" pairs programmers were already using all over the place, nothing more.