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[general] MSVC71 Warnings Off?
by Wu Yinghui, Freddie 15 Aug '06

15 Aug '06

Hi all, I guess this question could have been asked before. But I've failed to find an answer from my basic search from the web so far. So please try to bear with me if it is old stuff. Our development environment is using MSVC71 at the moment, and our coding standard requires warning level 4 and 64-bit compatiblity check of the compiler. But whenever I use some of the Boost library headers (most notably Boost.Function, Boost.Integer and Boost.uBLAS for now, and we have not started using most of the other libraries yet), there are tons of warnings from the compiler. As our development team view compiler warnings as important signs of potential problems in our own code, we'd like to suppress warnings from Boost headers (assuming that they are at least better tested than our code). So my question is: Is there a way for us to suppress warnings from Boost headers without affecting the warning level significantly on our own code? Any idea is greatly appreciated. :) Cheers, Freddie -- Wu Yinghui, Freddie Research & Development Software Engineer Volume Interactions Pte Ltd 1 Kim Seng Promenade, #12-01 Great World City East Tower Singapore 237994 Tel: +65 62226962 (Ext 216) Fax: +65 62226215 Email: yhwu(a)volumeinteractions.com URL: http://www.volumeinteractions.com Important: This message is intended for the recipient(s) addressed above. It contains privileged and confidential information. If you are not the intended recipient, please notify the sender immediately by replying to this message and then delete it from your system. You must not read, copy, use, or disseminate this communication in any form. Thank you.

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Re: [Boost-users] Boost serialization xml format and xml comments
by Todd Greer 15 Aug '06

15 Aug '06

Matt Schuckmann wrote: > Has anybody modified the grammar so that it will work with comments in > the xml files? As you investigate extending xml_iarchive to add this functionality, you may find it helpful to look at another example of extending xml_iarchive. In the Boost Vault, serialization/skip_xml_iarchive.zip extends xml_iarchive to of ignore unexpected xml elements. Though it does not handle comments, it may be sufficiently similar to your needs to justify glancing at its approach. -- Todd Greer <at Affinegy dot com, tgreer>

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Scripting using boost
by Shams 15 Aug '06

15 Aug '06

Hi, I want to simple scripting in my application, something like. IF window_title equals Firefox or window_title equals InternetExplorer open_kiosk() IF // nest if END_IF END_IF In this case I want to match the rule "window_title" and a parameter to that rule and upon seeing the text open_kiosk() I want to execute the real function. What would be the best boost libraries to use to achieve something like this? I am thinking of going with spirit and a combination of boost.regex or boost.xpressive. Thanks Shams

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A conflict in Boost?
by Ebbe Kristensen 15 Aug '06

15 Aug '06

I am developing a console program in Win32 using Borland C++ Builder 6 and Boost 1.33.1. I have a statically linked library that uses Boost tokenizer and regex. The main program uses Boost function and program_options. If my library is linked with the main program, the help output (generated by program_options) crashes with a null pointer access. This happens even if the library is not referenced in any way - it is enough just to link it in. Remove the library from the link list and the problem disappears. I'm fairly much out of ideas now so a bit of help would be very much appreciated. Ebbe

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[tuple] generating tuples from type lists
by imre＠u-tx.com 15 Aug '06

15 Aug '06

Hi, Is it possible to do this trick during compilation time? I was able to go from type lists to boost::cons but I can't find a way to make that last step. Thx. ImRe

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[BGL] dijkstra_shortest_path fails to call initialize_vertex
by Michael Barrientos 14 Aug '06

14 Aug '06

In Boost 1.33.1, the documentation at http://boost.org/libs/graph/doc/dijkstra_shortest_paths.html for the Dijkstra's Shortest Path algorithm says that the initialize_vertex(v,g) method of a Dijkstra visitor is invoked on each vertex in the graph before the start of the algorithm, but when I created a visitor with an initialize_vertex method, it was never called. I did some digging into the source, and found that when the Dijkstra's algorithm delegates to the Breadth First Search algorithm, it calls breadth_first_visit. However, only breadth_first_search calls initialize_vertex. Thus initialize vertex is never called. For now, I've decided to work around it without patching BGL, but can this be fixed in a future version?

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[Serialization] possible solns to vector of vectors ptr corruption
by Dan Notestein 14 Aug '06

14 Aug '06

Hi Robert, Any thoughts about my ideas for fixing the vector of vectors ptr corruption issue? I've reiterated my early msg below. If you don't have time to investigate, I would be willing to work on fixing the problem, if you don't mind me bugging you with questions occassionally. regards, Dan Notestein Original Message: ----------------------- Robert Ramey wrote: > Dan Notestein wrote: >> The other bug appears to be in the way moveable_objects_recent and >> moveable_objects_end are being set prior to calling >> reset_object_address. My assumption is the intent here is to modify >> the addresses of "trackable" sub-objects contained within the vector >> element being moved, so that ptrs will be hooked back up correctly, >> but the moveable ptrs are being set up in such a way that the vector >> elements (TObject) of the sub-vector (ObjectVector) are getting their >> addresses modified when the stack version of TObjectContainer is >> copied to the vector. > >> This seems wrong, because the TObjects are >> allocated on the heap, so their addresses should not be updated in >> the object_vector_id table when the ObjectVector is copied. The end >> result is that I'm getting bad pointers to the TObjects after >> deserialization. > > TObjects are de-serialized to the heap then added to the vector. > Since the tracking saves the address TObject is serialized to, the > address would be on the stack. reset_object_address sets the tracked > address to the heap address after the item is appended to the vector. > > I thought I considered the case of a vector of vectors - but maybe > not. I would expect that the objects get theire addresses fixed up > twice- once when they are moved from the stack to the heap and > once when the vector container itself is moved from the stack to the > heap. Its possible that there is something missng . Yes, the TObjects are fixed up twice, but I think the second fixup is an error because vector<> doesn't really contain the data elements, it contains a ptr to the data elements. When the vector container is "copied" from the stack to the heap, the newly allocated internal vector element array will be randomly allocated from somewhere else in the heap, so using an offset based off the address of the new copy of the vector container won't work. I can think of two possible theoretical solutions to the problem: 1) Use the container::swap function to exchange internal data ptrs of the stack and heap copy of the vector. This gives the heap vector the ownership of the stack vector's elements. This seems the most efficient technique since it avoid reallocating and copy constructing the elements. There's also no need to fixup the ptrs to the elements using this technique. 2) Continue to use the copy constructor for the vector when transferring the vector from stack to heap, and use the internal array ptr inside the new copy of the vector to fixup the elements. This definitely seems like the lesser of the two options. I would have tried to make a fix for this, but the algorithm for handling the moveable ptrs that define the range of addresses to fixup was a little complicated for me to follow. In particular, I wasn't sure how to make the fixups take place so that truly "contained" data gets fixed up, while avoiding fixing up the data that is merely "pointed" to by data members (and hence shouldn't be fixed up when the container is copied). One idea I had was to keep around the size of the data objects being moved, so that the reset_address function could look for ptrs in the moveable_ptr range that have addresses between old_address and old_address+object_size. But I also figured there was a good chance that there is already information available somewhere on which items in the object_id table are "contained" vs "pointed to". best regards, Dan Notestein

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simple boost::bind question
by Manfred Doudar 14 Aug '06

14 Aug '06

Hello all: Hoping someone might help with a simple problem; how I might call a member on a boost::bind placeholder, see below ... #include <list> class Xtype { public: Xtype(int v) : value_(v) { } int the_value() const { return this->value_; } private: int value_; }; template <typename Predicate> class Excise { public: void operator()(std::list<Xtype>& li) const { li.remove_if(boost::bind(Predicate(), ::_1, 10)); } }; ... what I really want is something more like [, note the call of Xtype::this_value() ]: void operator()(std::list<Xtype>& li) const { li.remove_if(boost::bind(Predicate(), ::_1.the_value(), 10)); } But how do I achieve that (, if at all possible); as seemingly ::_1.the_value() is illegal/invalid code ? Thanks in advance, -- Manfred

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[Boost][multi_array] copying a float array to a particular dimension of a multi_array
by Sebastien Fortier 14 Aug '06

14 Aug '06

I would like to know if it is possible to use memcpy to copy a float array to a particular dimension of a multi_array. ex.: I declare a 3 dimension multi_array of floats typedef boost::multi_array < float, 3 > array_type3D_f_t; int dim1 = 2; int dim2 = 2; int dim3 = 4; array_type3D_f_t valueMatrix(boost::extents[dim1][dim2][dim3]); then for each 3rd dimension I would like to copy a float array into it using memcpy (the final real multi_array will contain approx 21 000 000 elements, and thts why I do wish to iterate ). for (int i = 0; i < dim3; ++i) { // iterate over each 3rd dimension of the multi_array float *arr = NULL; arr = (float*)malloc(sizeof(float) * dim1 * dim2); function(&arr) // fills in the array (2D contiguous (dim1 * dim2)) memcpy(&valueMatrix[something...], arr, sizeof(float) * dim1 * dim2) // I want to copy the vector into the multi_array's 3rd dimension } then when I want to access an element I simply do valueMatrix[1][1][1]; what i used to do is int level = 0; while(it1 != it2){ // it1 and it2 are iterators to a list of records holding the data float* arr; readData(it1, &arr); // read the data into the array for (int j = 0; j < dim2; ++j){ for (int i = 0; i < dim1; ++i){ valueMatrix[i][j][level] = datavec[ j * dim1+i ]; } } ++it1; // change level ++level; } I would like to replace the nested loops by a memcpy, is this possible? -- Sébastien Fortier

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[Lambda] Protecting expressions with "mixed placeholders"
by Irfan Adilovic 14 Aug '06

14 Aug '06

Hi all, Assuming "v" is an STL container, and "value" is a value the container can hold, I wish to do the following: ll::accumulate()(v.begin(), v.end(), true, _1 && (_2 != value)); which works: it returns true if all elements in the container are different from "value", false otherwise (might require a minute of thinking to come to that conclusion). Now I wish to make a lambda expression out of the above piece of code, which accepts "value" as the operator () argument, in order to be evaluated: bind(ll::accumulate(), v.begin(), v.end(), true, _1 && (_2 != value_placeholder)); where _1 and _2 should be protected but value_placeholder shouldn't (this is why I used "mixed placeholders" in the subject). In other words, should the bind-expression be evaluated with (value) as its operator() argument, only "value_placeholder" must be replaced by "value", the _1 or _2 placeholders must not. A simple protect: protect(_1 && (_2 != value_placeholder)) is obviously wrong, as "value_placeholder" cannot be replaced by "value" in an expression like: bind(ll::accumulate(), v.begin(), v.end(), true, protect(_1 && (_2 != value_placeholder)))(value); since "value_placeholder" itself, too, is protected. How to do this? I hope this was clear enough, I really tried. :-/ Regards, -- Irfy

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