On 09/01/2015 02:16 PM, Steven Schveighoffer wrote:> On 9/1/15 3:13 PM,
Daniel Kozak via Digitalmars-d-learn wrote:
>>
>>
>> Dne 1.9.2015 v 19:20 Steven Schveighoffer via Digitalmars-d-learn
>> napsal(a):
>>> On 9/1/15 12:49 PM, default0 wrote:
>>>> Hello
>>>>
>>>> A simple thing I stumbled across:
>>>>
>>>> int main()
>>>> {
>>>> import std.stdio;
>>>> import std.range;
>>>>
>>>> int[] d;
>>>> d ~= 10;
>>>> d ~= 20;
>>>> d.put(5);
>>>> writeln(d);
>>>>
>>>> return 0;
>>>> }
>>>>
>>>> Appenders work fine as output ranges, but arrays do not. The above
code
>>>> prints "20" (ie the 10 is removed). Is "put" not supposed to mean
>>>> "append one element"?
>>>
>>> put into an slice does not append, it fills in the front. This is
>>> because the "target" of a slice is the data it points at.
>>>
>>> Think of it as a buffer that you want to fill:
>>>
>>> int[20] buf;
>>> int[] outputRange = buf[];
>>> outputRange.put(10);
>>> outputRange.put(20);
>>>
>>> assert(buf[0..2] == [10,20]);
>> So it is something like this?:
>>
>> int main()
>> {
>> import std.stdio;
>> import std.range;
>>
>> int[] d;
>> d ~= [10];
>> d ~= [20];
>> d.front = 5;
>> d.popFront();
>> writeln(d);
>>
>> return 0;
>> }
>>
>
> I'm not following your code. What is the question?
>
> -Steve
I think Daniel is asking whether .put() on a slice is the equivalent of
assigning to front() and then popFront(). The answer is yes.
http://dlang.org/phobos/std_range_primitives.html#.put
http://ddili.org/ders/d.en/ranges.html#ix_ranges.slice,%20as%20OutputRange
Ali
