Gaze upon my creation and despair. Witness... Objective-C#++

template<typename T>
class BinaryOperationManager : NSObject
{
  IBinaryOperation Operation { get; private set; }
  T Left { get; private set; }
  T Right { get; private set; }
  
  - (T) performOperation
  {
    return [this.Operation performWithLeft:this.Left right:this.Right];
  }
  
  - (void) setLeftValue:(T)newValue
  {
    if (this.Left != nullptr)
    {
      throw [System.InvalidOperationException .ctor:"Left value already set"];
    }
    
    this.Left = newValue;
  }
  
  - (void) setRightValue:(T)newValue
  {
    if (this.Right != nullptr)
    {
      throw [System.InvalidOperationException .ctor:"Right value already set"];
    }
    
    this.Right = newValue;
  }
  
  - (instancetype) init:(IBinaryOperation)operation
  {
    this.Operation = operation;
    return this;
  }
  
  + (instancetype) new:(IBinaryOperation)operation
  {
    return [[[this class] alloc] init:operation];
  }
}

Some quick analysis of this... thing now that I've created it...

• Templates. There's nothing else I have to say.
• The use of nullptr I guess implies that NULL also exists and compares equal to zero here.
• [System.InvalidOperationException .ctor] shows that, somehow, this creature is, indeed, meant to be running on the CLR (your named-after-the-class constructor ends up as a static factory method named .ctor by the time the compiler is done with it, and yes, that's a valid name for a CLR method and you can find it and call it directly via reflection).
• Somehow [[[this class] alloc] init] is one of the least bad things here.
• Such a lovely API design, isn't it?