Why is std.algorithm so complicated to use?

[Timon Gehr]

On 07/09/2012 10:46 PM, bearophile wrote:
> Jacob Carlborg:
>
>> import std.algorithm;
>> import std.range;
>>
>> struct Foo {}
>>
>> auto f = Foo();
>> auto foos = [f];
>> auto foo = foos.map!(x => "foo");
>> auto bar = foo.chain("bar");
>
> I suggest to always compile with "-wi -property".
>

Both -property and -w/-wi are broken and their only merit so far is to
break my builds for no reason.

-wi spits out about 4000 lines of false (duplicate) warnings when run
against my code base.


>> This simple example result in the follow error:
>>
>> http://pastebin.com/E4LV2UBE
>>
>> Another example:
>>
>> auto str = ["foo", "bar"].map!(x => x);
>> auto f = str.sort();
>
> Map returns a lazy iterable. Generally you need an eager
> random-access iterable to sort (but it seems there are some
> exceptions like when you sort a zip...).
>

Actually you need a random-access range with assignable elements. Map
would need to be provided with an inverse mapping to support that.

zip has assignable elements when the source ranges do.