David Abrahams wrote:
[...] Very bad idea. There's no reason that the algorithm should give up the basic guarantee in that case. Consider:
template <class InputIterator> std::vector::assign(InputIterator,InputIterator)
That really gives the basic guarantee with no hidden assumptions.
It assumes that there are no invariants that require, for instance, that all the input is consumed.
[...] In case you think this is an "evil glossing over of detail",
I wouldn't call it "evil"...
there are actually lots of these assumptions lurking in standard requirements, but they still work very well. For example, if incrementing InputIterator actually had the side-effect of modifying the vector, how well do you think std::vector::assign would work? How understandable do you think the specification would be if all these kinds of details were actually spelled out?
...but I guess it's the difference between a theorist and an engineer. As a little of both, I would like to simultaneously argue for rigor and pragmatism. ;) Dave