hi.

the following (manually "dustmited" ;-)) code gives the error from subj on git HEAD:

=== ztest.d ===
  module ztest;

  auto streamAsRange(STP) (STP st) {
    static struct StreamRange(ST) {
    private:
      ST strm;
    public:
      void put (const(ubyte)[] data) { strm.rawWrite(data); }
    }
    return StreamRange!STP();
  }

  void zcompress(RO) (RO ro) {
    ubyte[1] obuf;

    void writeOBuf () {
      static if (is(typeof(() {
        ubyte[2] b;
        ro.put(b);
      }))) {
        ro.put(obuf);
      }
    }

    writeOBuf();
  }

  void test () {
    import std.stdio;
    auto fo = File();
    zcompress(streamAsRange(fo));
  }

  void main () {
  }
======

the strange thing is that this is heisenbug. if i comment out `static if` the module successfully compiles. i.e. changing `zcompress()` to this allows me to compile the code:

===
  void zcompress(RO) (RO ro) {
    ubyte[1] obuf;

    void writeOBuf () {
      ro.put(obuf);
    }

    writeOBuf();
  }
===

so the offending line is `ro.put(b);` (comment it out, and everything is working again).

am i doing something very wrong here, or this is really a compiler bug?

p.s. well, it's not a heisenbug, 'cause it reproducible. let's say that it's a... very strange bug. ;-)

p.p.s. sure, i can see where i'm creating a closure. but i can't see how that closure got to IR generator, as it is never executes, there is no need to generate code for it, and it should be removed after checking `static if` condition.

On Tuesday, 3 March 2015 at 07:26:13 UTC, ketmar wrote:
> hi.
>
> the following (manually "dustmited" ;-)) code gives the error from subj
> on git HEAD:
>
> === ztest.d ===
>   module ztest;
>
>   auto streamAsRange(STP) (STP st) {
>     static struct StreamRange(ST) {
>     private:
>       ST strm;
>     public:
>       void put (const(ubyte)[] data) { strm.rawWrite(data); }
>     }
>     return StreamRange!STP();
>   }
>
>   void zcompress(RO) (RO ro) {
>     ubyte[1] obuf;
>
>     void writeOBuf () {
>       static if (is(typeof(() {
>         ubyte[2] b;
>         ro.put(b);
>       }))) {
>         ro.put(obuf);
>       }
>     }
>
>     writeOBuf();
>   }
>
>   void test () {
>     import std.stdio;
>     auto fo = File();
>     zcompress(streamAsRange(fo));
>   }
>
>   void main () {
>   }
> ======

Reduced further:

----
module ztest;

struct StreamRange {
  ~this() {}
  void put() {}
}

void zcompress(StreamRange ro) {
  void writeOBuf() {
    enum e = is(typeof({ro.put();}));
    ro.put();
  }
  writeOBuf();
}

void main() {
  zcompress(StreamRange());
}
----

Looks like a compiler bug to me.