DIP 1008 Preliminary Review Round 1
Nick Treleaven via Digitalmars-d
digitalmars-d at puremagic.com
Mon May 22 05:00:30 PDT 2017
On Saturday, 20 May 2017 at 02:05:21 UTC, Jonathan M Davis wrote:
> What we would probably need would be to change msg is a
> function which generates a message so that derived classes can
> override that rather than passing a message string.
Further to Moritz's reply showing the existing toString overload
taking a delegate. This delegate is not @nogc. Otherwise I was
thinking of doing something like this:
//FIXME: uniqueToString should return @nogc UniquePtr!(const
char[])
import std.conv;
alias uniqueToString = to!(const char[]);
class MessageEx(E, sinkArgs...) : E
{
this(A...)(A args)
{
super(args);
}
//FIXME: delegate not @nogc
/*@nogc*/ override void toString(scope void delegate(in
char[]) sink) const
{
foreach (a; sinkArgs)
sink(uniqueToString(a));
}
}
unittest
{
auto x = 7;
throw new MessageEx!(Exception, "x = ", x)(null);
}
The result of uniqueToString would free any memory allocated
after the call to sink.
More information about the Digitalmars-d
mailing list