Hi Thorsten! --- Thorsten Ottosen <nesotto@cs.auc.dk> wrote:
Hi Jan,
This is not my final review, but just some comment and questions. It's based solely on my reading of the docs.
1. your rationale mentions many characteristics that I would expect of std::deque. Do you have any idea how big the performance difference is? The memory is allocated at once, that's the biggest difference.
2. You mention "Guarantee of basic exception safety" as a design criteria. I would expect many operations to have a stronger guarantee.
Of cource, some methods provide stronger guarantee, but in general the container povides just basic exception safety. For some methods (e.g. insert) it is impossible to provide stronger guarantees.
3. you write "In fact the circular_buffer is defined in the file boost/circular_buffer/base.hpp, but it is necessary to ". I don't see why the user should be bothered with this implementation detail.
You're right.
4. Type Requirements: don't T need to be Assignable too?
Just no!
5. you could remove one version of push_back and push_front by using default arguments. Similar for insert()/rinsert()
I don't know if this is good idea or not, but all STL implementations I've seen have containers with both methods (one with default param and one without).
6. What's the use of "return_value_type" ?return_value_type operator[] (size_type index) const Return the element at the index position. Should it not be const_reference?
return_value_type is just optimization. It is const_reference for objects and value_type for primitive types.
7. when you state contracts like Precondition: *(this).size() > index don't you mean (*this).size() ? I would prefer that you omitted this entirely.
This is just typo. Anyway I would retain the precondition.
8. maybe you should add const_pointer data() const ?
It is not possible. data() is mutating operation. See the source code.
9 I assume you provide the basic exception safety for set_capacity(). However, I think you could achieve the strong guarantee by (1) allocating the new buffer and (2) start to copy elements [might throw] (3) swap the two buffers upon completion. The same goes for resize(). Why are they both provided? (If you made resizes 2nd argument to be the bool, then how would they differ?]
Yes, it works exactly like this. But the statement about provided exception safety covers the whole container.
10. Can't the exception guarantee for the copy-constructor be stronger too? (and assign(), and push_back(), push_front(), insert() )
No for insert()/rinsert(), push_xxx(), data() and erase(). See the source code.
11. Some operations must be nothrow: swap(), size(), capaciity(), pop_back(), pop_front().
Yes, they are. It is not written explicitly in the documentation (there is just no "Exceptions" section for each method). Jan __________________________________ Do you Yahoo!? Yahoo! Search - Find what you�re looking for faster http://search.yahoo.com