Re: Getting a reference to an immutable string

[ag0aep6g via Digitalmars-d-learn]

On 02/10/2018 11:46 PM, David Zhang wrote:
This is what I'm talking about:
void createWindow( ... ) {

     assert( wndclassName.ptr ); //This fails

     HWND hwnd = CreateWindowW(
         wndclassName.ptr, //This too
         null,
         0,
         CW_USEDEFAULT, CW_USEDEFAULT,
         CW_USEDEFAULT, CW_USEDEFAULT,
         null,
         null,
         null,
         null
     );
}

wstring wndclassName = "wndclass_name"w;

That's not enough code to reproduce the issue. This works as far as I see:

----
import core.sys.windows.windef: HWND;
import core.sys.windows.winuser: CreateWindowW, CW_USEDEFAULT;

void main()
{
    assert( wndclassName.ptr );

    HWND hwnd = CreateWindowW(
        wndclassName.ptr,
        null,
        0,
        CW_USEDEFAULT, CW_USEDEFAULT,
        CW_USEDEFAULT, CW_USEDEFAULT,
        null,
        null,
        null,
        null
    );
}

wstring wndclassName = "wndclass_name"w;
----

But there is a recent regression on Windows that might be related. Do 
you also have a static constructor (`static this`) that uses 
`wndclassName`? If so, you might be hitting issue 18412.

https://issues.dlang.org/show_bug.cgi?id=18412

If you don't have a static constructor, it might be a different bug. In 
that case, please provide complete code so that we can get to the bottom 
of it.