Comment #0 by bearophile_hugs — 2011-02-14T11:03:24Z
D2 code. map() doesn't modify the input range, so I think this is correct (but I am not sure if it's correct. A mutable range of immutable items isn't the same thing as an immutable range):
import std.algorithm;
void main() {
auto u1 = uniq([1]);
auto m1 = map!q{ a }(u1); // OK
const u2 = u1;
auto m2 = map!q{ a }(u2); // Error
}
DMD 2.051 gives:
...\dmd\src\phobos\std\algorithm.d(109): Error: constructor std.algorithm.Map!(result,const(Uniq!(pred,int[]))).Map.this (Uniq!(pred,int[]) input) is not callable using argument types (const(Uniq!(pred,int[])))
...\dmd\src\phobos\std\algorithm.d(109): Error: cannot implicitly convert expression (r) of type const(Uniq!(pred,int[])) to Uniq!(pred,int[])
test4.d(6): Error: template instance std.algorithm.map!(" a ").map!(const(Uniq!(pred,int[]))) error instantiating
Comment #1 by bearophile_hugs — 2012-02-03T15:41:44Z
This seems related, DMD 2.058head:
import std.algorithm, std.array;
void main() {
auto s1 = "hello";
auto m1 = map!(c => c)(s1);
auto a1 = array(m1); // OK
auto s2 = "hello"d;
auto m2 = map!(c => c)(s2);
auto a2 = array(m2); // line 8, Error
}
...\dmd2\src\phobos\std\array.d(55): Error: result[i] isn't mutable
test.d(8): Error: template instance std.array.array!(Result) error instantiating
Comment #2 by robert.schadek — 2024-12-13T17:54:48Z