go/src/internal/weak/pointer.go

type Pointer …

// Make creates a weak pointer from a strong pointer to some value of type T.
func Make[T any](ptr *T) Pointer[T] { … }

// Strong creates a strong pointer from the weak pointer.
// Returns nil if the original value for the weak pointer was reclaimed by
// the garbage collector.
// If a weak pointer points to an object with a finalizer, then Strong will
// return nil as soon as the object's finalizer is queued for execution.
func (p Pointer[T]) Strong() *T { … }

//go:linkname runtime_registerWeakPointer
func runtime_registerWeakPointer(unsafe.Pointer) unsafe.Pointer

//go:linkname runtime_makeStrongFromWeak
func runtime_makeStrongFromWeak(unsafe.Pointer) unsafe.Pointer