Instances · Function

compareinstances

Check if two Instance references point to the same underlying object.

function compareinstances(object1: Instance, object2: Instance): boolean

Synopsis

How it works

Compares the underlying C++ Instance* pointers behind two userdata wrappers. Returns true if both wrappers point to the same Roblox engine Instance, regardless of whether the Lua references are the same object. This is the tool for verifying identity after cloneref().

Why rawequal fails

Each cloneref() call allocates a new userdata in Luau's heap. Lua's rawequal compares userdata addresses, so two different allocations are never equal. compareinstances dereferences the userdata to get the C++ pointer and compares at that level.

Usage

Equality with cloneref

print(compareinstances(game, game))             "cc">-- true
print(compareinstances(game, workspace))         "cc">-- false
print(compareinstances(game, cloneref(game)))    "cc">-- true
print(game == cloneref(game))                    "cc">-- false

Parameters

object1 Instance

The first Instance to compare.

object2 Instance

The second Instance to compare against.

Returns

boolean true if both references point to the same underlying game Instance.

Required with cloneref

Whenever you use cloneref, use compareinstances instead of == for reliable equality checks.