• mark (7/7) Jan 30 2020 In the D Cookbook it has as part of the FibonacciRange example:
• mark (4/11) Jan 30 2020 Oh, I understand now...
• Adam D. Ruppe (11/13) Jan 30 2020 (I'll answer here anyway just in case someone lands here via a

mark <mark qtrac.eu> writes:

In the D Cookbook it has as part of the FibonacciRange example:

 property FibonacciRange save() { return this; }

And in the description it says:

"...save, which returns a new range that is a copy of the current 
range and can be advanced independently..."

Why is this a *copy*? (For a copy (in C++) I'd have expected 
return *this.)

mark <mark qtrac.eu> writes:

On Thursday, 30 January 2020 at 10:31:08 UTC, mark wrote:
 In the D Cookbook it has as part of the FibonacciRange example:

  property FibonacciRange save() { return this; }

 And in the description it says:

 "...save, which returns a new range that is a copy of the 
 current range and can be advanced independently..."

 Why is this a *copy*? (For a copy (in C++) I'd have expected 
 return *this.)

Oh, I understand now...

Sorry for the noise but I don't know how to delete a premature 
post!

Adam D. Ruppe <destructionator gmail.com> writes:

(I'll answer here anyway just in case someone lands here via a 
web search.)

On Thursday, 30 January 2020 at 10:31:08 UTC, mark wrote:
 Why is this a *copy*? (For a copy (in C++) I'd have expected 
 return *this.)

In C++, `this` is a pointer, but in D, it is a reference. So 
assignment follows those semantics instead; `Foo a = this` does a 
copy assignment and if you want a pointer, you need to explicitly 
ask for one with the & operator: `Foo* a = &this;`

fun fact, old versions of D, ~11ish years ago, actually worked 
the same way as C++. But the reference one was generally nicer 
and you can turn it back to the pointer as needed so it got 
changed.