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;
}

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