Using array slices with C-style fread() from file

[uncorroded via Digitalmars-d-learn]

On Wednesday, 21 June 2017 at 18:58:58 UTC, tetyys wrote:
> On Wednesday, 21 June 2017 at 18:49:01 UTC, uncorroded wrote:
>> Is there a way of making this work with D slices? Can they be 
>> used as C-style pointers?
>
> What about this:
>
> @nogc ubyte[n] rand_bytes(uint n)() {
>     import core.stdc.stdio;
>     FILE *fp;
>     fp = fopen("/dev/urandom", "r");
>     ubyte[n] buf;
>     uint bread = 0;
>     while (bread < n) {
>         auto toread = n - bread;
>         auto read = fread(buf[bread .. $].ptr, ubyte.sizeof, 
> toread, fp);
>         bread += read;
>     }
>     fclose(fp);
>     return buf;
> }
>
> ?

Thanks a lot! That works. Did not know about the .ptr for a 
slice. Is there any way of making the function with @safe as 
well? I get the errors "cannot call @system function 
'core.stdc.stdio.fread,fopen,fclose'.