This is under Linux 64 with both dmd 2.066 (and latest gdc-4.9):
=================================================================
class ShapeSurface(T) {
public:
int formula();
int getSurfaceBy100() {
int surface;
surface = cast(T *)this.formula();
return surface*100;
};
};
class Square: ShapeSurface!Square
{
public:
int squareSize = 8;
override int formula() {
return squareSize*squareSize;
}
};
int main() {
Square square = new Square();
square.getSurfaceBy100();
return 0;
}
=================================================================
It fails with linker error:
dmd app.d
app.o:(.data._D3app31__T12ShapeSurfaceTC3app6SquareZ12ShapeSurface6__vtblZ+0x28):
undefined reference to
`_D3app31__T12ShapeSurfaceTC3app6SquareZ12ShapeSurface7formulaMFZi'
collect2: error: ld returned 1 exit status
--- errorlevel 1
OK, maybe the cast is broken (well, to a pointer...), so changed
this:
surface = cast(T *)this.formula();
into this:
T cls = cast(T)this;
surface = cls.formula();
giving:
dmd app.d
app.o:(.data._D3app31__T12ShapeSurfaceTC3app6SquareZ12ShapeSurface6__vtblZ+0x28):
undefined reference to
`_D3app31__T12ShapeSurfaceTC3app6SquareZ12ShapeSurface7formulaMFZi'
collect2: error: ld returned 1 exit status
--- errorlevel 1
So, if you could tell me:
1) Why the compiler defer to the linker
2) What is the CRTP equivalent here
Many thanks.
