Possible to auto-compare ustructs without equality operator?

[GRIMTEC]

Hi!

@cdonnellan

Even with C++ 20, I don’t think that will help since presumably every type within a struct will need its own equality operator and not every UE4 type necessarily does (FText, for instance, does not) and I like to avoid editing the engine code.

You could just define a free == operator, no need to change engine code (see below). The =default solution in C++20 is by far the nicest so I would go with that if you can.

@cdonnellan

I guess Memcmp could work but that just feels wrong somehow.

Your feeling is right definitely don’t use memcmp for comparing structs, it most likely won’t give you the correct result anyway.

If you can’t use C++20 I would do it this way:

inline bool operator==(const FText& lhs, const FText& rhs)
{
  return lhs.EqualTo(rhs);
}

inline bool operator==(const FKani_InventoryItemWidgetInfo& lhs, const FKani_InventoryItemWidgetInfo& rhs)
{
  return Tie(lhs.Label, lhs.Icon, lhs.bExists, lhs.bIsEmpty, ...)
      == Tie(rhs.Label, rhs.Icon, rhs.bExists, rhs.bIsEmpty, ...);
}

I find it a bit cleaner than comparing all members individually.