formattedRead can't work with tab delimiter input

[Ky-Anh Huynh]

On Tuesday, 19 September 2017 at 20:04:36 UTC, kdevel wrote:
> On Tuesday, 19 September 2017 at 13:28:22 UTC, Ky-Anh Huynh 
> wrote:
>> Hi,
>>
>> I want to read two fields from STDIN
>>
>>     string key;
>>     double value;
>>     line_st.formattedRead!"%s %f"(key, value);
>
> Well it's so different from C. I would use this:
>
> ---
> auto t = line_st.split.join (' ');
> t.formattedRead!"%s %f"(key, value);
> ---

Yes it's possible.

It's a little weird and it seems the "feature" (or bug) is not 
documented on https://dlang.org/phobos/std_format.html. Why a tab 
(`\t`) isn't considered as a space?