scope test_structure_customSerializer

sclass #X {
  settable int i;
  
  // _serialize can now return this to request standard serialization
  O _serialize() {
    ret i < 0 ? this : i;
  }
  
  static X _deserialize(O o) {
    ret new X().i((int) o);
  }
  
  [stdEq]
}

svoid test_structure_customSerializer() {
  X x = new X().i(5);
  S s = struct(x);
  S nameOfX = shortClassName(X);
  assertEqualsVerbose("cu " + nameOfX + " 5", s);
  assertEqualsVerbose(x, unstructure(s));
  
  x = new X().i(-5);
  s = print(struct(x));
  assertEqualsVerbose(x, unstructure(s));
}

Began life as a copy of #1035332