why does phobos use [0, 5, 8, 9][] instead of [0, 5, 8, 9] in examples?

Vladimir Panteleev via Digitalmars-d-learn digitalmars-d-learn at puremagic.com
Tue Apr 7 22:50:56 PDT 2015


On Wednesday, 8 April 2015 at 02:40:14 UTC, Timothee Cour wrote:
> Eg, code like this in std.algorithm:
> assert(equal(setSymmetricDifference(a, b), [0, 5, 8, 9][]));
> why not just:
> assert(equal(setSymmetricDifference(a, b), [0, 5, 8, 9]));
> ?

It's historic. DMD 2.041 changed the type of array literals from 
int[N] (i.e. fixed-length literals of static arrays) to int[] 
(dynamic arrays). Since [] means to take a slice of the entire 
static array, it would tell the compiler to create a static 
array, but only pass a slice of it to equal() instead of passing 
the entire static array by-value.


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