• Roel Mathys (12/12) May 17 2004 template Mix1() { this(int x) { printf("mix1\n"); }}
• Derek Parnell (56/72) May 18 2004 Confirmed, sort of...

Roel Mathys <roel.mathys yucom.be> writes:

template Mix1() { this(int x) { printf("mix1\n"); }}

class Bar
{
     int myx;
     //~ mixin Mix1;		==> wouldn't compile

     this() { myx = 15; }

     mixin Mix1;			==> placing it here compiles
}

int main() {
     Bar bar = new Bar();
     return 0;
}

Derek Parnell <derek psych.ward> writes:

On Tue, 18 May 2004 08:29:27 +0200, Roel Mathys wrote:

 template Mix1() { this(int x) { printf("mix1\n"); }}
 
 class Bar
 {
      int myx;
      //~ mixin Mix1;		==> wouldn't compile
 
      this() { myx = 15; }
 
      mixin Mix1;			==> placing it here compiles
 }
 
 int main() {
      Bar bar = new Bar();
      return 0;
 }

Confirmed, sort of...

With this code ...
//----------------------
template Mix1(alias y)
{
    this(int x) { y = x; printf("mix1\n"); }
}

class Bar
{
     int myx;

     this() { myx = 15; }
     //mixin Mix1!(myx);        // ==> placing it here compiles
     this(int x) { myx = x; printf("mix2\n");}
}

int main() {
     Bar bar1 = new Bar();
     Bar bar2 = new Bar(4);

     printf("1 %d, 2 %d\n", bar1.myx, bar2.myx);
     return 0;
}
//----------------------

I get ...

c:\temp>dmd mix
C:\DPARNELL\DMD\BIN\..\..\dm\bin\link.exe mix,,,user32+kernel32/noi;

c:\temp>mix
mix2
1 15, 2 4

... but when I replace the hard coded ctor(int) with the mixin ...
//----------------------
template Mix1(alias y)
{
    this(int x) { y = x; printf("mix1\n"); }
}

class Bar
{
     int myx;

     this() { myx = 15; }
     mixin Mix1!(myx);        // ==> placing it here compiles
     //this(int x) { myx = x; printf("mix2\n");}
}

int main() {
     Bar bar1 = new Bar();
     Bar bar2 = new Bar(4);

     printf("1 %d, 2 %d\n", bar1.myx, bar2.myx);
     return 0;
}
//----------------------

... I get this ...
c:\temp>dmd mix
mix.d(17): constructor this () does not match argument types (int)

So it appears that any ctor brought in by a mixin is ignored if any ctor
already exists for the class.

-- 
Derek
18/May/04 6:28:40 PM