On Tue, Jan 5, 2010 at 3:06 PM, markus2004x <markus2004x@yahoo.com> wrote:
1) On the boost user guide I read: "However unbounded_array is aimed at optimal performance. Therefore unbounded_array does not model a Sequence like std::vector does". I do not quite understand this statement. An std::vector is memory contiguous and access happens by offset. How can an unbounded beat this?
I suppose that optimal performance was written with regards to memory consumption: unbounded_array consume just enough memory to store the number of object that it was asked to (it is not the case for std::vector, cause it requires amortized allocation time when growing and does so by allocating more than it actually requires). Under-laying container is still a contiguous array, so access time through operator[] is identical to std::vector. Btw, there is a typo in the doc page: "When resized unbounded_array will reallocate it's... " should be "its" not "it's", I think. http://www.boost.org/doc/libs/1_41_0/libs/numeric/ublas/doc/unbounded_array.... Cannot help for 2). Sorry. Sylvain