On Dec 2, 2007 11:04 AM, Mathias Gaunard <mathias.gaunard@ens-lyon.org> wrote:
Meta-Programming, as used in Boost.MPL and others, allows to compute arbitrary values at compile-time, in a Turing-complete manner.
However, something like generating unique identifiers at compile-time, which would be fairly useful, requires some kind of entropy source to create a random seed.
One can maybe extract some entropy from macros such as __DATE__ and __TIME__, using both preprocessing and templates.
Among you boosters, which are well known for your interesting in meta-programming, is there someone who ever tried to look into this?
OK, this is funny - on GCC 4.0.1/darwin, I was able to: #include __DATE__ which means you can have a date-based seed given a huge number of files to include. I don't know if this works with all compilers though. Too bad #include __TIME__ doesn't work, because of ":"s in the literal... but maybe someone can take this further and figure something out. Stjepan