Re: Who discovered the type erasure technique in C++?
on Wed Aug 20 2008, Andrei Alexandrescu <andrei-AT-cs.washington.edu> wrote:
gpderetta wrote:
On Aug 17, 4:48 pm, "Roshan Naik" <naikr...@gmail.com> wrote:
I am wondering who first figured out how to do this in C++ ?
Boost::Function and Boost::Expressive libraries both use it and my Castor
library (mpprogramming.com/cpp) also relies on it very heavily. I thought
Eric Niebler might be the one, but at NWCPP he told me that he too had
picked it up from somewhere else.
I learned this technique from the ACE papers (where is named External
Polymorphism):
http://www.cs.wustl.edu/~schmidt/PDF/External-Polymorphism.pdf
The paper is dated 1996, but I wouldn't be surprised if the technique
was older.
The technique described there doesn't necessarily lead to value
semantics (but then again, neither does type erasure)
No doubt the idiom was used for a while, but assigning the right names
to idioms is important too. I recall the first time I heard "type
erasure" in context with the C++ way of doing it was in a messageby Dave
Abrahams, I think on Boost.
Thanks, but somehow I doubt I came up with that one. The archives show
that Doug Gregor made the first mention of "type erasure" on Boost
(http://article.gmane.org/gmane.comp.lib.boost.devel/48924/match=type+erasure)
--
Dave Abrahams
BoostPro Computing
http://www.boostpro.com
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