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[PREDEF] Review ends today
by Joel Falcou 29 Feb '12

29 Feb '12

The review of Boost.PRedef by Rene Rivera is ending today, February 29th. I recall to all people wanting to submit a formal review to do so. Regards

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[Predef] Pre-review comments
by Mathias Gaunard 28 Feb '12

28 Feb '12

Misc ==== - This stuff partially exists in Boost.Config. How will this be integrated? - AMD stands for Advanced Micro Devices, not American Micro Devices - The whole set of C and C++ standard libraries doesn't seem to be covered. Are we supposed to infer it from the compiler or operating system? Naming ====== - BOOST_ARCHITECTURE_ is maybe a bit long. Have you considered a shorter name like BOOST_ARCH_ALPHA ? Same comment for BOOST_LANGUAGE_ - BOOST_LANGUAGE_XXX uses a STD prefix for most languages except for Objective-C. How about dropping the STD prefix? Also why not use CXX instead of CPP? - Standard C library is identified by LIBC, but standard C++ library is identified by LIBSTD. I find that confusing, it should be orthogonal. I take it LIBCXX wasn't chosen due to possible confusion with libc++. It's their fault for choosing a ridiculously broad name. glibc is often just called libc as well, yet this is not a problem. - BOOST_CXX_GNUC might be better as BOOST_CXX_GNU or BOOST_CXX_GCC - BOOST_OS_DRAGONFLY_BSD might be better as BOOST_OS_BSD_DRAGONFLY to indicate that "macro refinement" goes left to right. It could be BOOST_OS_BSD_FREEBSD for FreeBSD. Compiler frontend vs backend ============================ The BOOST_CXX_ macros is used to define both frontends (BOOST_CXX_CLANG, BOOST_CXX_EDG) and backends (BOOST_CXX_LLVM) and things that can be both (BOOST_CXX_GNUC) As for BOOST_CXX_CYGWIN, I have no idea what it's doing there. Cygwin should be exclusively in BOOST_OS_CYGWIN. The compiler is a normal GCC. As such it might be hard to tell which set of flags might be defined at the same time. Maybe the solution would be to split the set of frontends and backends, with each value in each set being mutually exclusive. Most compilers do not decouple frontends and backends, so it will end up with a lot of unnecessary duplication though. Non-mutually exclusive macros ============================= Currently, the only macros that are not mutually-exclusive (outside of the CXX macros outlined above, since they cover two different things) are the BOOST_OS_BSD macros along with BOOST_OS_UNIX and BOOST_OS_SVR4. It might be a good idea to expand on that on the architecture side (i.e. any x86, 32 or 64 bit), and the compiler side (GCC-like compilers). There are many variants of ARM as well, and a new 64-bit ARM will be released soon. The design needs to be flexible enough to integrate this. It might be good as well to put a clear distinction between a set of mutually-exclusive macros and more global macros that can cover several configurations. My use-cases ============ Just a few real use cases for which I use custom code in my software today, and that I'd be glad to replace: - Work-around a bug in the GCC frontend - Use a feature present in GCC-like frontends - Work-around a bug in the GCC backend - Define special versions of functions for x86 both 32- and 64-bit - Define special versions of functions for x86-64 only - Use special code for Windows or POSIX operating systems (for that, I currently use BOOST_SYSTEM_WINDOWS_API / BOOST_SYSTEM_POSIX_API)

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Re: [boost] [git] neglected aspects
by David A. Greene 28 Feb '12

28 Feb '12

> The only downside (I can see) with GIT is that it has a bit of a learning curve. It is a bit more complicated but I believe (and experienced myself) that a lot of that learning curve is unnecessarily steep due to the way many of the tutorials out there are written. For some reason most of them start out describing the guts and inner workings of git (blobs, trees, packs, etc.) rather than teaching workflows. The one great exception I've found to this is Scott Chacon's fabulous _Pro_Git_ (http://progit.org/book) It teaches you how to use git to manage sources. Reading that is what make it "click" for me. -Dave

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Is there interest in portable integer overflow detection, with policy based handling?
by Ben Robinson 28 Feb '12

28 Feb '12

The implementation is complete, with 5 policies created (and users can always create and use more). The policies are: ignore_overflow throw_overflow assert_overflow saturate_overflow nan_overflow The implementation is fully portable, and it provides integer types which can be used like the builtin integers, except they will trigger their policy on an overflow. Also, this library will integrate seamlessly with the Boost Constrained Value Library (contributed by Robert Kawulak). Does this pique anyone's interest? Thank you, Ben Robinson

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Please use BOOST_ASSERT_MSG(x, "message") instead of BOOST_ASSERT(x && "message")
by Mathias Gaunard 28 Feb '12

28 Feb '12

Several libraries, including Boost.Array, use things like BOOST_ASSERT( i < N && "out of range" ); This causes warnings with EDG-based compilers. It would be nice if library authors could replace this with something like BOOST_ASSERT_MSG( i < N, "out of range" ); Not only will it make those warnings disappear, it will also enable users to use those messages more efficiently in custom assert handlers. Thank you.

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[test] Dynamic linking problem?
by Matthijs Möhlmann 28 Feb '12

28 Feb '12

Hello all, Attached a testcase how I use the boost test library. Compiling goes well, but when I try to run it I get a 'symbol lookup error': matthijs@hammer % ./main ./main: symbol lookup error: ./main: undefined symbol: _ZN5boost9unit_test9ut_detail24auto_test_unit_registrarC1ENS0_13basic_cstringIKcEE I compile my files with the following lines: g++ -o main.o -c -I/usr/src/boost_1_49_0 -g -Werror -Wall -std=c++0x main.cpp g++ -o test.o -c -I/usr/src/boost_1_49_0 -g -Werror -Wall -std=c++0x test.cpp g++ -o main -L/usr/src/boost_1_49_0/stage/lib main.o test.o -lboost_unit_test_framework This is done with a fresh install of boost 1.49. (Compiled with ./bootstrap.sh && ./b2 -j3) Compiler: gcc-4.6 If I use the most recent version of trunk (r77131) then everything works as expected. If more information is needed, please let me know. Regards, Matthijs Möhlmann

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[uBLAS] array_adaptor, shallow_array_adaptor, interoperability and bugs
by Guillermo Ruiz Troyano 28 Feb '12

28 Feb '12

It is my first post. I still write worst in English than in C++. I hope don't mess it up… INTEROPERABILITY I'm been trying to use array_adaptor and shallow_array_adaptor to modify data with uBLAS. Yes, both classes are undocumented but it is useful (not this implementation) in some cases to have this kind of adaptor. For example: // Statistics accumulator for regression, correlation, etc. struct simple_regression { void operator()(double x, double y) { … } double mean_x; double var_x; double mean_y; double var_y; double covar; vector_wrapper<double> v() { … } // Return vector with a reference array adapter }; Now, you need (for example) to interpolate two accumulators. Then you should to be able to do: simple_regression sr, sr1, sr2; … double w = 0.5; sr.v() = sr1.v()*w+sr2.v()*(1-w); And you don't want that uBLAS copies data from you objects to inner containers continuously. UNDOCUMENTED ATTEMPT array_adaptor<T> has deep copy semantics. You can to construct an array_adaptor that use the external data, but vector call to copy constructor and this makes a copy: struct point { double x; double y; double z; }; point p = { 1, 2, 3 } array_adaptor<double> a(3, &p.x); // Ok, a holds p address vector<double, array_adaptor<double> > v(a); // v now holds a new address! Well, a bit confusing class. If the only purpose of this class template is to pass plain data as arguments. Why not to put that constructor in unbounded_array and bounded_array? unbounded_array(size_t size, T* data) : size_(size), data_(new value_type[size]) { std::copy(data, data+size, data_); } Then, I found shallow_adaptor_array, more dangerous and funny. It has shallow copy semantics and a dummy shared_array with reference counting... ¿? // Yes, I want troubles… #define BOOST_UBLAS_SHALLOW_ARRAY_ADAPTOR struct point { double x; double y; double z; }; void test() { point p = { 1, 2, 3 } shallow_array_adaptor<double> a(3, &p.x); // Ok, a holds p address vector<double, shallow_array_adaptor<double> > v(a); // Ok, v holds p address v += v; // Ok, now p = { 2, 4, 6 } v /= 2; // Ok, now p = { 1, 2, 3 } v = 2*v; // ¡¡¡What!!! p = { 1, 2, 3 } } // Dummy functor of shared_array in shallow_array_adaptor called, ok. When you assign v with an expression, this constructs a temporary and then swaps between the temporary and v. Here is the issue: class shallow_array_adaptor<T> : … { ... // Swapping BOOST_UBLAS_INLINE void swap (shallow_array_adaptor &a) { if (this != &a) { std::swap (size_, a.size_); std::swap (own_, a.own_); std::swap (data_, a.data_); // This is definitely infidelity } } ... }; This is not a good idea. This member function should have a dual behavior: class shallow_array_adaptor<T> : … { ... // Swapping BOOST_UBLAS_INLINE void swap (array_adaptor& a) { if (own_ && a.own_) { // If they own the data do wife-swapping if (this != &a) { std::swap(size_, a.size_); std::swap(own_, a.own_); std::swap(data_, a.data_); } } else if (&data_[0] != &a.data_[0]) std::swap_ranges(data_, data_+size_, a.data_); // Childs is another thing } ... }; Modifying this function I get: void test() { point p = { 1, 2, 3 } shallow_array_adaptor<double> a(3, &p.x); // Ok, a holds p address vector<double, shallow_array_adaptor<double> > v(a); // Ok, v holds p address v = 2*v; // Ok, now p = { 2, 4, 6 } and v holds p address } // 0kills of dynamic memory WHY NOT? 1. An unbounded_array and bounded_array constructor for C plain arrays and copy semantics. 2. To discontinue this adaptor_array (with a #ifndef) or modify. Its behavior can do it point nº1. 3. To fix, test and document shallow_array_adaptor (or another name). It should be useful. Yes, I know about memory leaks. But there are things like vector proxies, iterator ranges, etc. The problem comes when you have not a clear semantic. Regards, Guillermo Ruiz Troyano.

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[exception] RFC: patch for printing stacktraces during exceptions.
by Brett Lentz 27 Feb '12

27 Feb '12

Hi folks! It's been a few months since I last mailed the list. I've been working on bringing some forked changes from the Passenger project into Boost due to their more general applicability. With some help, I've got a working patch against SVN trunk that enables one of Passenger's more useful features: obtaining exception stacktraces all the way through the stack. However, due to the size of the patch and some namespacing choices made by the Phusion people, I'd like to get some feedback on this patch to ensure it's suitable for being brought into Boost. First, there's some helper classes that Phusion has put in an "oxt" namespace that I'm not really sure where they should be put or if suitable analogues already exist within Boost. For the current version of the patch, these files are simply put into 'boost/oxt' until I have a better location for them. Second, the current patch uses boost::tracable_exception. I'd like to confirm whether that is acceptable or whether I should move this to a different location in the boost namespace. Finally, any other comments about this patch are welcome. I have attached both the patch, and some example code that will demonstrate the functionality. The patch and a simple example are available here: http://wakko666.fedorapeople.org/boost/ ---Brett.

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Re: [boost] Is there interest in static code analysis?
by Ben Robinson 27 Feb '12

27 Feb '12

I would be interested in that static analysis tool. Thank you, Ben Robinson Sent from my Verizon Wireless smartphone Antony Polukhin <antoshkka(a)gmail.com> wrote: >Hi, > >I`ve recently found a tool and organization, that specializes on >static code analysis for C/C++. They already interact with some famous >open source projects and successfully find bugs. Looks like for >open-source projects they help for free. > >If someone is interested, I can send their web address in private >message (don`t want to ad on mailing list) > >Best regards, >Antony Polukhin > >_______________________________________________ >Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost

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vsix - template_profiler extension
by Brandon Kohn 27 Feb '12

27 Feb '12

Hello, I've put together a Visual Studio 2010 extension package which wraps the functionality of Steven Watanabe and Domagoj Saric's template_profiler to create a template profile tool. It also adds a command to profile the build time of a project or a single C++ file. Both functions are accessed from the context menu in the solution explorer tree-view. It's still fairly young and could use some kicking about. Are there any VC10 users here that would be interested in giving it a try? Cheers, Brandon

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