string to char* in betterC

[Abby via Digitalmars-d-learn]

What is the proper way to get char* from string which is used in 
c functions? toStringz does returns:

/usr/include/dmd/phobos/std/array.d(965,49): Error: TypeInfo 
cannot be used with -betterC

and I think string.ptr is not safe because it's not zero 
termined. So what should I do? realloc each string with /0?

Thank you for your help