Help passing D strings to C libs

[Jonathan M Davis]

On Monday, March 14, 2011 10:54:57 Trass3r wrote:
> > I'm having trouble passing D strings (char[]) to SDL, in particular
> > SDL_LoadBMP(), I keep receiving a segfault.
> > 
> > Heres the code:
> > 
> > void setImg(string path) {
> > 
> >     // concat null terminating char to string and cast to c type string
> > 
> > when
> > 
> >     // passing to SDL_LoadBMP()
> >     path ~= "\0";
> >     image = SDL_LoadBMP( cast(char*)path );
> > 
> > }
> > 
> > and the value of path is "./resources/cannon.bmp"
> > 
> > I'm using SDL 1.2.14 and DMD 1.067 on Ubuntu 10.10
> 
> Well strings are put into read-only space on Linux and I guess this is
> also the case for D1.
> Since you are doing a ~= it probably tries to alter that value and crashes.

No. If it can't concatenate in place, then it will reallocate the array. The 
fact that it was in read-only memory is irrelevant. It just means that 
reallocation is guaranteed instead of being only possible.

- Jonathan M Davis