On 6/1/2011 12:52 AM, Carl M. Johnson wrote:
So, my proposal is that += by itself should not cause x to be considered a local variable.
Right now, 'augmented assigment' is uniformly what it says: an assignment with augmented behavior. 'expr1 op= expr2' is *defined* as being the same as 'expr1 = expr1 op expr2' except that expr1 is evauluated just once*, and if expr1 evaluates to a mutable, the op can be done in place. Some consider the second exception to be a confusing complication and a mistake. Your proposal would require a rewrite of the definition and would add additional complication. Some would then want another exception for when expr1 evaluates to a mutable within an immutable (see Paul Svensson's post). While I do understand your point, I also value uniformity. -1 * It is actually more complicate than than. Expr1 is partially evaluated just once to an internal reference rather than to an object. That reference is then used once to fetch the existing object and once again to rebind to the new or mutated object. Still, it is one behavior for all occurrences. -- Terry Jan Reedy