MettleM0110Borrowed interior pointer outlives its scope
Reported by the compiler as an error or warning.
mettle explain M0110A pointer into a stack value (a field, an array element) escapes the scope that owns the value, e.g. saved to an outer variable inside a block. When the block exits the pointee dies.
Fix: shorten the pointer's lifetime to the value's scope, or move the value itself to the outer scope / heap.