MethodHandle strlen = CLinker.getInstance().downcallHandle(
CLinker.systemLookup().lookup("strlen").get(),
MethodType.methodType(long.class, MemoryAddress.class),
FunctionDescriptor.of(CLinker.C_LONG, CLinker.C_POINTER)
);
try (var scope = ResourceScope.newConfinedScope()) {
var cString = CLinker.toCString("Hello", scope);
long len = (long)strlen.invokeExact(cString.address()); // 5
}