toString refactor in druntime

[Daniel Murphy via Digitalmars-d]

"Benjamin Thaut"  wrote in message news:m2m3j2$ciu$1 at digitalmars.com...

> They wouldn't get any uglier than they already are, because the current 
> toString functions within druntime also can't use std.format.
>
> An example would be to toString function of TypInfo_StaticArray:
>
> override string toString() const
> {
> SizeStringBuff tmpBuff = void;
> return value.toString() ~ "[" ~ cast(string)len.sizeToTempString(tmpBuff) 
> ~ "]";
> }
>
> Would be replaced by:
>
> override void toString(void delegate(const(char)[]) sink) const
> {
>   SizeStringBuff tmpBuff = void;
> value.toString(sink);
> sink("[");
> sink(cast(string)len.sizeToTempString(tmpBuff));
> sink("]");
> }
>
> The advantage would be that the new version now ideally never allocates. 
> While the old version allocated 3 times of which 2 allocations end up 
> beeing garbage right away.
>
> Also I rember reading that the long term goal is to convert all toString 
> functions to the sink version.

It's very ugly compared to the formattedWrite version, and it does increase 
the line count compared to the current version (this is the main 
disadvantage of the sink-based toString IMO).  If this is as bad as it gets, 
PR approval shouldn't be a problem.