copy on write

[88888 Dihedral]

在 2012年1月14日星期六UTC+8上午6时48分29秒，Evan Driscoll写道：
> On 01/13/2012 03:20 PM, Neil Cerutti wrote:
> > They perform the same action, but their semantics are different.
> > operator+ will always return a new object, thanks to its
> > signature, and operator+= shall never do so. That's the main
> > difference I was getting at.

Well, in any associative operation with an identity implemented in a computer language  personally I believe the operator overloading part in C++ is   another teasing trick.

 
Do we have to work out the algebra here?