[boost] Sizes, signed and unsigned integers, MPL and Fusion

Subject: [boost] Sizes, signed and unsigned integers, MPL and Fusion
From: Mathias Gaunard (mathias.gaunard_at_[hidden])
Date: 2012-09-10 04:57:27

Hi folks,

I am writing this message to bring to your attention ticket #7304
<https://svn.boost.org/trac/boost/ticket/7304>

Sizes of fusion sequences are of type 'int', because it mimics MPL.
However, sizes of standard containers, some of which are fusion 
sequences, are of type std::size_t, which is unsigned.

This seems a bit inconsistent, and can lead to unexpected 
signed/unsigned mismatch warnings in certain scenarios.

Should both MPL and Fusion be modified to use unsigned size types?
I think it is best to discuss this with the whole of Boost.