BitArray - incomplete implementation?
anony via Digitalmars-d-learn
digitalmars-d-learn at puremagic.com
Fri Jan 23 17:40:55 PST 2015
On Saturday, 24 January 2015 at 00:13:34 UTC, Laeeth Isharc wrote:
> Hi.
>
> Should the following code work?
>
Yes, that error is caused by a bug of
BitArray(https://issues.dlang.org/show_bug.cgi?id=13806). Having
"init" function broke template constraints of "chain"(and must
break dozen of other templates).
pragma(msg, ElementType!(BitArray[])) // prints 'pure nothrow
void(bool[] ba)' - ElementType uses "init" property to determine
types.
> import std.bitmanip;
> import std.stdio;
> import std.array;
> import std.range:chain;
>
> void test()
> {
> int[] a=[1,2,3,4,5];
> int[] b=[5,4,3,2,1];
> int[] c = chain(a,b).array; // chain two arrays of int
> writefln("%s",c);
> }
>
> void test2()
> {
> BitArray a;
> a.init([1,0,1,0]);
> BitArray b;
> b.init([0,1,0,1]);
> BitArray[] d;
> d~=a;
> d~=b;
> BitArray[] c=chain([a],[b]).array; // cannot chain two
> bitarrays
> BitArray[] e=chain(d,d).array; // cannot chain two arrays of
> bitarrays
> writefln("%s",c);
> }
>
> int main(string[] args)
> {
> test();
> test2();
> return 1;
> }
>
> bitmanip.d(23): Error: template std.range.chain cannot deduce
> function from argument types !()(BitArray, BitArray),
> candidates are:
> /usr/include/dmd/phobos/std/range.d(2493):
> std.range.chain(Ranges...)(Ranges rs) if (Ranges.length > 0 &&
> allSatisfy!(isInputRange, staticMap!(Unqual, Ranges)) &&
> !is(CommonType!(staticMap!(ElementType, staticMap!(Unqual,
> Ranges))) == void))
> bitmanip.d(24): Error: template std.range.chain cannot deduce
> function from argument types !()(BitArray[], BitArray[]),
> candidates are:
> /usr/include/dmd/phobos/std/range.d(2493):
> std.range.chain(Ranges...)(Ranges rs) if (Ranges.length > 0 &&
> allSatisfy!(isInputRange, staticMap!(Unqual, Ranges)) &&
> !is(CommonType!(staticMap!(ElementType, staticMap!(Unqual,
> Ranges))) == void))
> bitmanip.d(24): Error: declaration bitmanip.test2.c is already
> defined
> bitmanip.d(25): Error: template std.range.chain cannot deduce
> function from argument types !()(BitArray[], BitArray[]),
> candidates are:
> /usr/include/dmd/phobos/std/range.d(2493):
> std.range.chain(Ranges...)(Ranges rs) if (Ranges.length > 0 &&
> allSatisfy!(isInputRange, staticMap!(Unqual, Ranges)) &&
> !is(CommonType!(staticMap!(ElementType, staticMap!(Unqual,
> Ranges))) == void))
>
> I cannot seem to concatenate - directly, or using chain - two
> bitarrays, or two arrays of bitarrays.
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