I don't really see how variable length arrays save time? Those seem like a feature that belongs in C++ but definitely not in C imho.

However, what I like to see in C are "//" style comments, declaring variables at other places than start of scope, the integer types with bit size specified, etc...

But the VLA's? They're created on the stack, right? So you'd need malloc for large ones anyway.

What actually would save time (for the coder of course) in C, imho, would be a way to automatically clean up resources no matter where you exit a scope or function. Something like destructors do in C++. E.g. if you could type something like "onleave free(myresource);" which would execute what you type after "onleave" whenever the scope exits.