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From: David Abrahams (dave_at_[hidden])
Date: 2006-05-29 13:53:35

Adrián Etchevarne <adrian.etchevarne_at_[hidden]> writes:

> Problem:

> How can I get a tuple type from a tuples::cons<> list ?

> example:

> given the type:

> cons<int, cons<float, cons<int, null_type> > >


> obtain

> tuple<int, float, int>



> Real problem:

> I need to insert a type T at the beginning of a tuple, how I can do this?


> example

> given the type T and tuple<int, float>, obtain a tuple<T, int, float>

That's a lot easier to solve, in some sense, than the "Problem:"

above. The cons list *is* a valid tuple. So to inserta new type at

the front, just write

    const<T, the-shorter-cons-list>

You might also want to look at

which was recently accepted into Boost.

Dave Abrahams
Boost Consulting

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