// Phase 4.2 — parameterized protocol as a runtime VALUE type. `VL(s64)` is a // 16-byte protocol value {ctx, vtable} (a plain protocol was already, but a // parameterized one used to resolve to a 0-field stub). A conforming struct // `xx`-erases into it, and method dispatch uses the bound type-arg // (`get -> T` becomes `get -> s64` for `VL(s64)`). #import "modules/std.sx"; VL :: protocol(T: Type) { get :: () -> T; } IntCell :: struct { v: s64; } StrCell :: struct { s: string; } impl VL(s64) for IntCell { get :: (self: *IntCell) -> s64 => self.v; } impl VL(string) for StrCell { get :: (self: *StrCell) -> string => self.s; } main :: () -> s32 { a : VL(s64) = xx IntCell.{ v = 42 }; print("a.get={}\n", a.get()); // 42 (T = s64) b : VL(string) = xx StrCell.{ s = "hi" }; print("b.get={}\n", b.get()); // hi (T = string) 0 }