On Tuesday, 18 December 2018 at 12:07:37 UTC, Andrey wrote:
Hi,
Have array:
enum array = ["qwerty", "a", "baz"];
Need to reverse and sort array elements to get this result:
[a, ytrewq, zab]
Did this:
enum result = array.map!(value => value.retro()).sort();
Got:
Error: template std.algorithm.sorting.sort cannot deduce
function from argument types !()(MapResult!(__lambda1,
string[])), candidates are:
/usr/include/dmd/phobos/std/algorithm/sorting.d(1849,1):
std.algorithm.sorting.sort(alias less = "a < b", SwapStrategy
ss = SwapStrategy.unstable, Range)(Range r) if ((ss ==
SwapStrategy.unstable && (hasSwappableElements!Range ||
hasAssignableElements!Range) || ss != SwapStrategy.unstable &&
hasAssignableElements!Range) && isRandomAccessRange!Range &&
hasSlicing!Range && hasLength!Range)
How to solve the problem?
There are in fact to instances of the same problem here:
The problem is map and retro are lazy - they return an element at
a time, and so can't be sorted. You will need to make a arrays
from them:
import std.array : array;
import std.range : retro;
import std.algorithm : map, sort;
enum arr = ["qwerty", "a", "baz"];
enum result = arr
.map!(value => value.retro().array)
.array // This creates an array from map's
result.
.sort();
--
Simen
