On Friday, December 13, 2013 09:00:20 Dfr wrote: > Hello > > I trying to write simple wrapper around pcre and have problem > passing strings to it. As i understood, the best way is > std.string.toStringZ. > > So, my code look like: > > string pattern = "...."; > pcre_compile2( toStringz(pattern), options, &errcode, &errmsg, > &erroffset, cast(char*)null); > > This gives me error: > > Error: function pcre_compile2 (char*, int, int*, char**, int*, > char*) is not callable using argument types (immutable(char)*, > int, int*, char**, int*, char*) > > Any ideas for better way to do this task ?
The problem is that toStringz returns immutable(char)* (because string is immutable(string)[]), and your function is taking char*. It will work to pass the result of toStringz to a C function which takes const char* (since immutable will implicitly convert to const), but immutable doesn't implicitly convert to mutable, and casting immutable mutable is almost always a bad idea. The easiest solution would be to use std.utf.toUTFz. e.g. auto cstr = str.toUTFz!(char*)(); or you could do something like auto cstr = str.dup.ptr; In either case, what you're doing is allocating a new char[] which holds the same elements as the original string and getting its ptr property so that you have a char*. - Jonathan M Davis
