The demise of T[new]

[Michel Fortin]

On 2009-10-18 17:05:39 -0400, Walter Bright <newshound1 at digitalmars.com> said:

> The purpose of T[new] was to solve the problems T[] had with passing 
> T[] to a function and then the function resizes the T[]. What happens 
> with the original?
> 
> The solution we came up with was to create a third array type, T[new], 
> which was a reference type.
> 
> Andrei had the idea that T[new] could be dispensed with by making a 
> "builder" library type to handle creating arrays by doing things like 
> appending, and then delivering a finished T[] type. This is similar to 
> what std.outbuffer and std.array.Appender do, they just need a bit of 
> refining.
> 
> The .length property of T[] would then become an rvalue only, not an 
> lvalue, and ~= would no longer be allowed for T[].
> 
> We both feel that this would simplify D, make it more flexible, and 
> remove some awkward corner cases like the inability to say a.length++.
> 
> What do you think?

I never liked T[new] much from the beginning, so good riddance. :-)

But seriously, disallowing '~=' but not '~'? I can already see the newbies:

Q: Why can't I write '~=' as a shortcut for '~' on a slice? It works 
fine for every other operator, everywhere else.
A: Because appending is not very efficient.
Q: So '~' is more efficient than '~='?
A: Hum, no. They're both as inefficient, but...

-- 
Michel Fortin
michel.fortin at michelf.com
http://michelf.com/