Idea: Introduce zero-terminated string specifier

[Piotr Szturmaj]

Paulo Pinto wrote:
> On Monday, 1 October 2012 at 09:42:08 UTC, Piotr Szturmaj wrote:
>> Jakob Ovrum wrote:
>>> On Monday, 1 October 2012 at 09:17:52 UTC, Piotr Szturmaj wrote:
>>>> Adam D. Ruppe wrote:
>>>>> On Saturday, 29 September 2012 at 02:11:12 UTC, Alex Rønne Petersen
>>>>> wrote:
>>>>> Also this reminds me of the utter uselessness of the current
>>>>> behavior of
>>>>> "%s" and a pointer - it prints the address.
>>>>
>>>> Why not specialize current "%s" for character pointer types so it will
>>>> print null terminated strings? It's always possible to cast to void*
>>>> to print an address.
>>>
>>> It's not safe to assume that pointers to characters are generally null
>>> terminated.
>>
>> Yes, but programmer should know what he's passing anyway.
>
> The thinking "the programmer should" only works in one man teams.
>
> As soon as you start having teams with disparate programming knowledge
> among team members, you can forget everything about "the programmer
> should".

I experienced such team at my previous work and I know what you mean. My 
original thoughts was based on telling writef that I want print a 
null-terminated string rather than address. to!string will surely work, 
but it implies double iteration, one in to!string to calculate length 
(seeking for 0 char) and one in writef (printing). With long strings 
this is suboptimal. What about something like this:

struct CString(T)
     if (isSomeChar!T)
{
     T* str;
}

@property
auto cstring(S : T*, T)(S str)
     if (isSomeChar!T)
{
     return CString!T(str);
}

string test = "abc";
immutable(char)* p = test.ptr;

writefln("%s", p.cstring); // prints "abc"

Here the char pointer type is "annotated" as null terminated string and 
writefln can use this information.