[ASDAlexander77]

A @cppvtable class numbered its methods as vtable slots by declaration order, so a binding had to declare a placeholder for every slot it didn't call, overloads (which MSVC orders its own way) were numbered by hand, and a slot off by one called another C++ method with no error.

The decorator is now @cpp, and only a method with @slot(N) is virtual:

Method in a @cpp class	Meaning
@slot(N) f(): T;	C++ virtual method, slot N (base slots counted); any order, gaps allowed
f(): T; named like a base's slot	override: keeps that slot, as in C++
@linkname("?f@C@@QEAAHH@Z") f(): T;	C++ non-virtual method, called by its symbol as fn(this, args)
f(): T { ... } without @slot	TypeScript's own helper, not in the vtable

• Skipped slots are null in a class implementing C++ methods; two methods in one slot are an error.
• Errors: a bodiless method with neither @slot nor @linkname (a forgotten @slot isn't a silent wrong call), an abstract method without @slot, an override's @slot not matching its base's, @slot on an ordinary class, a non-virtual C++ method returning a struct (not supported yet).
• @cppvtable is an error saying it is now @cpp: an unknown decorator would have left an old binding an ordinary class.
• Ordinary classes are unchanged. Exported @cpp classes carry each method's @slot in their declarations.

Breaking: existing @cppvtable bindings (native_ts_graphics core/nvrhi.ts) must move to @cpp + @slot(N) before they're built with a tslang that has this.

Tests

• Existing @cpp tests converted to @slot with their positional numbers.
• tests/00cpp_slot.ts: out-of-order and skipped slots, a derived class, a TypeScript helper (AOT and JIT).
• test-jit-cppvtable-abi: calls a real non-virtual C++ method by its MSVC / Itanium mangled name; Counter gets a TypeScript helper (the Itanium vtable check still sees only the C++ slots).
• The export/import test calls a helper across modules.
• One compile-error test per new rule.
• Full suite (windows-msbuild-2026-release): 4042/4042 passed (1 already disabled).

Docs: docs/cppvtable-classes.md becomes docs/cpp-classes.md.

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