[Bug c/50645] old issue - deprecated conversion from string to char*

["redi at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50645

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-10-07 00:41:25 UTC ---
(In reply to comment #0)
> 
> If I declare:
> 
> const char    *DowNames[] = {
>         "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun",
>         NULL
>     };
> 
> as just char* instead of const char*, YES I WOULD LIKE TO GET A WARNING.

So you want a warning if non-const pointers point to const data. Makes sense.

> HOWEVER, if I have a function:
> 
> myfunction(char *buf) {}
> 
> I'd like to be able to call it like this 
> 
> myfunction("hello world") 
> 
> ... WITH NO 'deprecated conversion from string to char*' WARNING

So you don't want a warning if a non-const pointer points to const data.
Huh?  How is that different from the earlier case.

> because char* as a parameter should be able to take a string as an argument --
> this makes sense.

Why?  If a function takes char* it means it can change the contents of the char
or chars at that address, why is a warning not appropriate if you call it with
an argument that might cause a runtime error if the function changes the data?

> It's annoying to have to cast (char*)"hello world" every place in code, as
> programmers always used to use, simply "hello world". (i know an option is to
> change the warning level -- but that has other issues.)

Or, if your function really doesn't change the data, you could always fix its
signature to be myfunction(const char*).

Or use C, instead of C++ (you do realise the warning you're complaining about
is a C++ warning, not a C one, right?)

> PLEASE UNDEPRECATE!  (Keep things simple, keep backward compatibility, as the
> old-school way is often best, designed that way for simplicity!)

That conversion is deprecated by the C++ standard, GCC cannot un-deprecate it.
Talk to the C++ committee (who will tell you to stop living in the 1970s and
get over it, type safety is a good thing.)