Extending readf?

[monarch_dodra]

Not so long ago, there was an amazing article about how user 
defined types and formated writes behaved:

http://wiki.dlang.org/Defining_custom_print_format_specifiers

As cool as it is, I was writting a little user defined type, and 
I wanted to the the contrary: un-format it to read it.

Apparently. You can't do it. I'm not talking about "you can't 
customize it", I mean "you can't do it, at all."

For all the bashing C++'s ">>" and "<<" operators get, they at 
least work both ways for UDTs.

I found this thread:
http://forum.dlang.org/thread/mailman.2107.1335304266.4860.digitalmars-d-learn@puremagic.com
And the forked thread:
http://forum.dlang.org/thread/20120424215103.GA28525@quickfur.ath.cx

Which basically amounts to "Maybe do you want to open this 
discussion in the main D newsgroup?" and the suggestion "Does it 
make sense to add a fromString() method to user-defined types for 
this? D's toString support is awesome (you can basically call 
to!string on just about anything and it works). It would be nice 
to have similar support for the reverse operation." To which no 
one added anything.

That was in .learn, so it might not have gotten much coverage.

How complicated wold it be to have things specify a "fromString" 
method? Is it worth the effort?

Is it possible to have a "fromString" default generated? If not, 
would it be OK if formatted read could work for only on things 
that define "fromString"?

In any case, it feels like a pretty wide hole in regards to a 
high level statically typed language.