Excluded from wscript v1

Deliberately absent in wscript v1:

Borrow checker, &/&mut, lifetimes, exceptions, async, threads, implicit conversions, truthiness, and bitwise operators.

Shipped since v1, so no longer absent: script-to-script imports, string interpolation in every string literal, compound assignment (+=), associated functions, generic functions (not host-callable), and unit families on numeric types.