toChars buffer access?

[Salih Dincer]

On Sunday, 23 August 2020 at 19:18:51 UTC, Steven Schveighoffer 
wrote:
> I was about to reach for 
> core.internal.string.signedToTempString [1] to convert a number 
> into a temp string yet again. And I thought, maybe there's 
> something in Phobos by now.
>
> And lo and behold! There's std.conv.toChars [2]
>
> But... it just gives me a range of char, and not an actual 
> string. So my intended purpose (to use it as a string key for 
> an associative array) means I have to copy it to a local buffer 
> anyway.
>
> No matter, right? It probably just stores the number and gives 
> me access to each character as it parses. Oh wait, no. It 
> actually stores it as a char[20], but doesn't give me access.
>
> Which leaves me with the only option of doing:
> ```d
> auto s = someNumber.toChars;
> char[20] buf;
> import std.algorithm : copy;
> copy(s.save, buf[0 .. s.length]);
>
> auto v = aa[buf[0 .. s.length]];
> ```
> But my goodness, it would just be so easy if it gave access to 
> the buffer:
> ```d
> auto s = someNumber.toChars;
> auto v = aa[s.data]; // @system access to buffer, unsafe!
> ```
> And this is discounting the fact that I not only am copying the 
> buffer *again*, but doing it one character at a time.
>
> So would it be a problem to allow this accessor, even if it's 
> @system? Or should I just keep importing core.internal?
>
> -Steve
>
> [1] 
> https://github.com/dlang/druntime/blob/9f0f6e49fb379841c7934b6049f87dab0adfe53c/src/core/internal/string.d#L113
>
> [2] https://dlang.org/phobos/std_conv.html#toChars

I also faced this problem. Anyone have a solution?

SDB at 79