The problem is that, while in many ways an improvement over traditional coding practice, the subset of C++ associated with the Core Guidelines (GSL stands for "(Core) Guidelines Support Library") has turned out to be a dead-end when it comes to memory safety. In fact it formalizes the depenedency on intrinsically unsafe elements like native pointers, std::shared_ptr, etc. I mean, with "regular" C++ you're not actually obligated to use those intrinsically unsafe elements. With the Core Guidelines you are.

SaferCPlusPlus[1] is an alternative subset of C++ that doesn't have that same problem. It achieves memory safety by simply excluding the intrinsically unsafe elements and providing memory-safe alternatives.

> All compile time checks.

Not quite in reality. One small issue with the GSL, for example, is that its not_null pointer class does a run-time check on every pointer dereference[2]. SaferCPlusPlus can enforce "not null"ness at compile-time.

A bigger example, for instance, is the situation where you want to allow multiple threads to simultaneously modify different parts of an array. With SaferCPlusPlus, this is straightforward and safe [3]. With the GSL/Core Guidelines, less so.

I don't know how much these technical considerations factor into (or will factor into) popularity of adoption. I don't know how big the intersection is of the sets of developers who take code safety seriously and those who remain interested in C++.

[1] shameless plug: https://github.com/duneroadrunner/SaferCPlusPlus

[2] https://github.com/Microsoft/GSL/blob/1c95f9436eae69c9b93159...

[3] https://github.com/duneroadrunner/SaferCPlusPlus/blob/278b40...