Re: filter!(not!(predicate))(someInputRange) does not compile

[Andrei Alexandrescu]

On 1/19/11 5:53 PM, Jens Mueller wrote:

Hi,

I cannot make the following compile.

import std.functional;
import std.array;
import std.algorithm;
import std.stdio;

void main() {
     auto numbers = [0, 1, 2, 3, 4, 5];

     bool alwaysTrue(uint a) { return true; }
     alias not!(alwaysTrue) alwaysFalse;

     numbers = array(filter!(alwaysTrue)(numbers));
     writeln(numbers);
     numbers = array(filter!(alwaysFalse)(numbers)); // does not compile
     writeln(numbers);
}

The line with alwaysFalse fails with:
/path/to/../src/phobos/std/algorithm.d(854): Error: constructor
std.algorithm.Filter!(not,int[]).Filter.this cannot get frame pointer to
not

Any ideas what I'm doing wrong or workarounds?

Jens

Place the call to not!alwaysTrue in a local function inside main:

    bool alwaysFalse(uint a) { return not!alwaysTrue(a); }


Andrei