D2 toStringz Return Type

[Mike Parker]

I'm curious as to why toStringz in D2 returns const(char)* instead of 
just a plain char*. Considering that the primary use case foe the 
function is interfacing with C code, it seems rather pointless to return 
a const(char)*.

Consider the D2 versions of the function declarations in the std.c 
package. The 'const char *' declarations from C are replaced with 'in 
char*' from D. To what end? The C side doesn't know and doesn't care 
about const declarations in D. You could add any sort of modifier you 
want on the D side and it would serve no real purpose.

Then consider all of the existing (and future) bindings to C libraries 
out there. The vast majority have this sort of function prototype:

=====================
// from the C header
void someFunc(const char*);

// in D
extern(C) void someFunc(char*);
======================

This works with D1, but anyone using this library with D2 will either 
have to change such prototypes to include the 'in' modifier, or cast 
every call to toStringz.

I'm updating Derelict now to work with D2 and found this to be 
incredibly annoying. But before I go through every API Derelict binds to 
  in order to figure out which char* parameters should get the 'in' 
modifier, I thought I'd ask here if there is any real purpose in 
requiring this sort of thing?

Is there any major use case for toStringz other than passing 
null-terminated strings to C functions? If not, then having a 
const(char)* return type is really superfluous. It doesn't do anything! 
Can we just remove the const?