return type of std.algorithm.mutation.reverse changed for good?

biocyberman biocyberman at gmail.com
Thu May 24 12:43:48 UTC 2018


On Thursday, 24 May 2018 at 12:34:38 UTC, Steven Schveighoffer 
wrote:
> On 5/24/18 8:08 AM, rikki cattermole wrote:
>> On 25/05/2018 12:06 AM, biocyberman wrote:
>>> I am testing with DMD 2.078.2 locally. This tiny snippet 
>>> works on dlang's online editor: https://run.dlang.io/is/nb4IV4
>>>
>>> But it does not work on my local dmd.
>>>
>>> import std.algorithm.mutation;
>>> import std.stdio;
>>> char[] arr = "hello\U00010143\u0100\U00010143".dup;
>>> writeln(arr.reverse);
>>>
>>> Error: template std.stdio.writeln cannot deduce function from 
>>> argument types !()(void)
>>>
>>> The document says reverse returns a range: 
>>> https://dlang.org/phobos/std_algorithm_mutation.html#reverse
>> 
>> https://docarchives.dlang.io/v2.078.0/phobos/std_algorithm_mutation.html#reverse
>> 
>
> This doesn't quite tell the whole story.
>
> An array used to have a .reverse property that the compiler 
> implemented, which returned the array after reversing it. So in 
> history, this actually worked without std.algorithm.
>
> You get a nice history of what happens using "all dmd versions" 
> on run.dlang.io. If you remove the "mutation" part from the 
> import, you get:
>
> Up to      2.071.2: Success with output: 𐅃Ā𐅃olleh
> 2.072.2 to 2.074.1: Success with output:
> -----
> onlineapp.d(6): Deprecation: use std.algorithm.reverse instead 
> of .reverse property
> 𐅃Ā𐅃olleh
> -----
>
>            2.075.1: Failure with output:
> -----
> onlineapp.d(6): Error: template std.stdio.writeln cannot deduce 
> function from argument types !()(void), candidates are:
> /path/to/dmd.linux/dmd2/linux/bin64/../../src/phobos/std/stdio.d(3553):
>       std.stdio.writeln(T...)(T args)
> -----
>
> 2.076.1 to 2.077.1: Failure with output:
> -----
> onlineapp.d(6): Error: template std.stdio.writeln cannot deduce 
> function from argument types !()(void), candidates are:
> /path/to/dmd.linux/dmd2/linux/bin64/../../src/phobos/std/stdio.d(3571):
>       std.stdio.writeln(T...)(T args)
> -----
>
>            2.078.1: Failure with output:
> -----
> onlineapp.d(6): Error: template std.stdio.writeln cannot deduce 
> function from argument types !()(void), candidates are:
> /path/to/dmd.linux/dmd2/linux/bin64/../../src/phobos/std/stdio.d(3657):
>       std.stdio.writeln(T...)(T args)
> -----
>
> Since      2.079.0: Success with output: 𐅃Ā𐅃olleh
>
> -Steve

@Rikki and Steve: Many thanks for the good tips. I upgraded to 
dmd.2.080.0 now, but the server seems to be very slow. It's 
another story anyway.

  % ./install.sh dmd                                               
                                                                   
                                                                   
                                                                   
                                               !9767
Downloading and unpacking 
http://downloads.dlang.org/releases/2.x/2.080.0/dmd.2.080.0.linux.tar.xz

curl: (28) Operation too slow. Less than 1024 bytes/sec 
transferred the last 30 seconds
Failed to download 
'http://downloads.dlang.org/releases/2.x/2.080.0/dmd.2.080.0.linux.tar.xz'


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