- Boost - lists.boost.org

IOStreams formal review
by John Torjo 07 Sep '04

07 Sep '04

------------------------------------------- * What is your evaluation of the design? Very nice and clean. ------------------------------------------- * What is your evaluation of the implementation? ------------------------------------------- * What is your evaluation of the documentation? Documentation is very nice and neat. Small comments: tutorial.html: " The Iostreams Library allows users to create a standard input stream or stream buffer by defining a classes with a single member function read and several member types." Q: What do you mean, by 'several member types'? "Buffering and the ability to put back characters come for free." Q: Can I putback multiple chars, or just one? 3.4 Output Filters Here your examples use 'filtered_streambuf', while in the Reference section, you use 'filtering_streambuf'. Is this a typo? examples.html I love the presidential filter ;) policy_based_streams.html: I think you should visually show that streambuf_facade owns the policy (the source). I had to look through the code to realize that. I have later realized that you did say at the beginning " by delegating to a contained instance of a policy class". Maybe emphasize the "contained instance" (bold or something)? filtering_streambuf.html: Again, by looking at the code, it seems that you own the streambufs. Is that so? If it is, please state it in the docs (this is more of a general issue - it applies to other classes as well). I am worried about this, since I want to know what I need to destroy manually, and what is destroyed automatically for me. General issues: I'm not sure if mixing streambuf and stream concepts is such a good idea. As I've seen in your examples, you only use streams. Tnus, you don't use streambufs directly. While having streambuf_facade is DEFINITELY a good idea, I think you should have an "Advanced" section, where you talk about the streambufs. The rest of us are quite happy with having and using stream_facade. ------------------------------------------- * What is your evaluation of the potential usefulness of the library? Very useful ------------------------------------------- * Did you try to use the library? With what compiler? Did you have any problems? VC7.1 Compiled some examples - they worked ok, after I slightly modified the jamfile. (which makes me not like bjam even more - it makes it so hard to build even trivial things) ------------------------------------------- * How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? Reviewed it several times (in the past as well). ------------------------------------------- * Are you knowledgeable about the problem domain? Yes ------------------------------------------- * Do you think the library should be accepted as a Boost library? Be sure to say this explicitly so that your other comments don't obscure your overall opinion. I think this library should be ACCEPTED. Best, John -- John Torjo Freelancer -- john(a)torjo.com Contributing editor, C/C++ Users Journal -- "Win32 GUI Generics" -- generics & GUI do mix, after all -- http://www.torjo.com/win32gui/ -- v1.3beta released - check out splitter/simple_viewer, a File Explorer/Viewer all in about 200 lines of code! Professional Logging Solution for FREE -- http://www.torjo.com/code/logging.zip (logging - C++) -- http://www.torjo.com/logview/ (viewing/filtering - Win32) -- http://www.torjo.com/logbreak/ (debugging - Win32) # Boost.Iostreams Library Build Jamfile # (C) Copyright Jonathan Turkanis 2004 # Distributed under the Boost Software License, Version 1.0. (See accompanying # file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.) subproject libs/io/build ; # bring in compression-options template import ../build/compression ; local ZLIB = [ cond $(NO_ZLIB) $(NO_COMPRESSION) : : zlib ] ; local LIBBZ2 = [ cond $(NO_LIBBZ2) $(NO_COMPRESSION) : : bzip2 ] ; SOURCES = file_descriptor memmap $(ZLIB) $(LIBBZ2) ; lib boost_io : ../src/$(SOURCES).cpp [ unless $(NO_COMPRESSION) : <template>compression-options ] : # build requirements [ common-names ] # magic for install and auto-link features <include>$(BOOST_ROOT) <sysinclude>$(BOOST_ROOT) : debug release # build variants <debug><runtime-link>static <release><runtime-link>static ; dll boost_io : ../src/$(SOURCES).cpp [ unless $(NO_COMPRESSION) : <template>compression-options ] : # build requirements [ common-names ] # magic for install and auto-link features <define>BOOST_IO_DYN_LINK=1 # tell source we're building dll's <runtime-link>dynamic # build only for dynamic runtimes <include>$(BOOST_ROOT) <sysinclude>$(BOOST_ROOT) : debug release # build variants ; install io lib : <lib>boost_io <dll>boost_io ; stage stage/lib : <lib>boost_io <dll>boost_io : # copy to a path rooted at BOOST_ROOT: <locate>$(BOOST_ROOT) # make sure the names of the libraries are correctly named: [ common-names ] # add this target to the "stage" and "all" psuedo-targets: <target>stage <target>all : debug release # build variants ; # end

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Re: [boost] IOStreams formal review
by Reece Dunn 07 Sep '04

07 Sep '04

Carlo Wood wrote: >On Tue, Sep 07, 2004 at 07:41:25AM +0200, John Torjo wrote: > > Why binary? I could see lots of uses for text as well. > >Because text is a special case of binary. If the library >supports streambufs, and when it would support the concept >of 'message blocks', then "text" just means that you'd >detect End-Of-Line sequences and cut the stream into >messages that are in fact lines of text. Bring a text stream means that you do \r\n <--> \n normalization for the streams (or whatever end of line encoding your OS uses). That, AFAIK, is the only percievable difference between the two modes according to the standard. (I am not sure how text streams handle '\0'). >Actually putting that text in a std::string and doing >some work on it should be in user code imho. This would be inefficient in most contexts. Especially if you have a complex filter chain with inbuilt buffers that are only concerned with character-by-character processing. I understand that in some cases it would be useful to see the data as a sequence of lines stored as std::string, but then isn't that what: std::string str; std::ifstream in( "data.txt" ); while( std::getline( in, str )) { std::cout << "line = " << str << '\n'; } is for? Regards, Reece _________________________________________________________________ It's fast, it's easy and it's free. Get MSN Messenger today! http://www.msn.co.uk/messenger

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Boost serialization: release configuration linker errors
by Andrew Favell 07 Sep '04

07 Sep '04

Robert, Thanks for the info, actually yes, I am using version 1_31. Is that a mistake by me? Can you tell me where the CVS tree is, thanks, Andy Favell -- ___________________________________________________________ Sign-up for Ads Free at Mail.com http://promo.mail.com/adsfreejump.htm

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typeless trampoline
by Bronek Kozicki 07 Sep '04

07 Sep '04

Hi I factored out trampoline class from my ext_auto_ptr_090 . I'd like to know how it works on modern compilers. I was able to test it on few compilers I use for regression tests: msvc71 (passed with FAULTY set) como 4.3.3 with backend msvc71 mingw 3.3.1 mingw 3.4.1RC I will be happy to know how it works with other compilers. Maybe boosters could test this code with some compilers? I'm especially interested in recent Intel and CW versions. I think that it might be useful utility in boost, provided I can make it enough functional (passing arguments to function is first thing to be added). B. #include <cassert> #include <cstdio> #include <utility> // Copyright Bronislaw Kozicki 2003-2004. Use, modification and // distribution is subject to the Boost Software License, Version // 1.0. (See http://www.boost.org/LICENSE_1_0.txt ) #ifndef __COMO__ # if defined(_MSC_VER) && (_MSC_VER <= 1310) # define FAULTY # endif // _MSC_VER #endif // __COMO__ template <bool> struct static_assert; template <> struct static_assert<true> {}; class trampoline { private: typedef void(*_pf_t)(void *); template <typename Functor> struct _lever_t; template <typename Functor> struct _lever_t<Functor *> { static_assert<sizeof(Functor*) == sizeof(void *)> size; union convert { Functor* f; void* p; }; static void exec(void * p) { convert c; c.p = p; (*c.f)(); } static std::pair<_pf_t, void *> init(Functor* f) { convert c; c.f = f; return std::pair<_pf_t, void *>(&exec, c.p); } }; // the one and the only data std::pair<_pf_t, void *> _pf; public: template <typename Functor> trampoline(Functor f) : _pf(_lever_t<Functor>::init(f)) {} trampoline(const trampoline& rh) : _pf(rh._pf) {} trampoline& operator=(const trampoline& rh) { _pf = rh._pf; return *this; } void operator()() { _pf.first(_pf.second); } }; static int tmp = 0; static const int tmp_f = 2; void f() { printf("f()\n"); tmp = tmp_f; } static const int tmp_g = 5; static const int tmp_g_f = 6; #ifdef FAULTY int g() { int i = tmp_g_f; printf("faulty "); #else int g(int i = tmp_g) { #endif tmp = i; printf("g(%d)\n", i); return tmp; } static const int tmp_A = 10; struct A { void operator()() const { printf("A::operator()()\n"); tmp = tmp_A; } }; trampoline f1() { return trampoline(&f); } trampoline g1() { return trampoline(&g); } trampoline A1() { static A a; return trampoline(&a); } int main() { trampoline l = f1(); l(); assert(tmp == tmp_f); l = g1(); l(); assert(tmp == tmp_g || tmp == tmp_g_f); l = A1(); l(); assert(tmp == tmp_A); }

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[mpl] mpl::if_ workaround for digital mars
by Daniel James 07 Sep '04

07 Sep '04

Aleksey, I've just been trying the new version of mpl on Digital Mars. The attached patch fixes the bug that sometimes causes mpl::if_ to fail. The problem is that the class template gets redeclared with different parameter names by bind.hpp, and this confuses the compiler. When it instantiates the class, it uses the wrong names. The fix is just to make sure bind.hpp is included before mpl::if_ is defined. thanks, Daniel

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Thread-safe containers
by Tony Juricic 07 Sep '04

07 Sep '04

Browsing through the older posts I could not find any relevant discussion. What is the opinon on implementing thread-safe containers? Java library has them, for example, and, since extending existing containers to be thread safe using locks is a work each client would have to repeat, it looks like a good candidate for standardized library implementation. As for more efficient lock-free impleentations (using CAS) Microsoft has (relatively recently) added singly linked lock-free list to Win32 API. There are examples of lock-free implementations of doubly linked STL list using older Valois algorithm. I would argue that most of multi-threaded programs need thread-safe containers. Tony

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[mpl][vacpp] recurrent problems with name confusions
by Joaquín Mª López Muñoz 07 Sep '04

07 Sep '04

Visual Age 6.0 for AIX complains about the way list iterator is defined "/home/tk/boost_regression/boost/boost/mpl/list/aux_/iterator.hpp", line 30.47: 1540-0416 (S) "next" cannot be declared because its name has already been used. The offending line is typedef l_iter<typename next<Node>::type> next; I guess it'd suffice with rewriting it as: typedef l_iter<typename boost::mpl::next<Node>::type> next; This error (and similar ones in range_c, transform_view, joint_view, pair_view,filter_view) seem to share the same pattern: the compiler complains whenever it finds a structure like this: struct foo { ... name ... typedef ... name; }; a possible workaround (though I cannot test it) is to rewrite this as: struct foo { ... boost::mpl::name ... typedef ... name; }; I don't know if vacpp is meant to be supported by MPL. In case it is, maybe this can be of some help. Best, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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serialization - build shared libs
by Neal Becker 07 Sep '04

07 Sep '04

I'm using current boost cvs. Building with bjam -sTOOLS=gcc stage, builds only archive (.a) versions of serialization libs. I need shared (.so). What needs to be done?

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Problems building --v2 (x86_64)
by Neal Becker 07 Sep '04

07 Sep '04

PYTHON_ROOT=/usr PYTHON_VERSION=2.3 PYTHON_LIB_PATH=/usr/lib64/python2.3 bjam --v2 ...patience... ...found 986 targets... ...updating 113 targets... MkDir1 bin.v2 MkDir1 bin.v2/libs MkDir1 bin.v2/libs/test MkDir1 bin.v2/libs/test/build MkDir1 bin.v2/libs/test/build/gcc MkDir1 bin.v2/libs/test/build/gcc/debug gcc.compile.c++ bin.v2/libs/test/build/gcc/debug/execution_monitor.o gcc.compile.c++ bin.v2/libs/test/build/gcc/debug/cpp_main.o gcc.link.dll bin.v2/libs/test/build/gcc/debug/boost_prg_exec_monitor.so /usr/bin/ld: bin.v2/libs/test/build/gcc/debug/execution_monitor.o: relocation R_X86_64_32 can not be used when making a shared object; recompile with -fPIC bin.v2/libs/test/build/gcc/debug/execution_monitor.o: could not read symbols: Bad value collect2: ld returned 1 exit status

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Interest in custom numeric formatting?
by Stefan Slapeta 07 Sep '04

07 Sep '04

Hi all, I've recently developed a small lib for custom numeric formatting, which is part of many programming languages. You pass any number and a format string which controls the formatting. Some examples (using the US locale): num_format ( 3332123.3332, "$#,0.00" ) -> "$3,332,123.33" num_format ( 123, "#.00" ) -> "123.00" num_format ( 12, "000" ) -> "012" num_format ( 12.9, "000" ) -> "013" (rounded!) num_format ( -123.1, "#.#;-#.00" ) -> "-123.10" num_format ( -123, "$#;- $0.00;0" ) -> "- $123.00" num_format ( 0, "0.00;-0.00;<Zero>" ) -> "<Zero>" num_format ( 1000000, "#,#,.00" ) -> "1,000.00" Short explanation for the format string: . marks the decimal separator , has two functions: - if the format string contains any "," before, but not immediately before the decimal separator, there will be thousand separators in the output. - if the format string contains any "," immediately before the decimal separator, the number will be divided by the number of "," characters multiplied by 1000. 0 If there is no digit in this position, there will be a 0 in the output string # If there is a digit in this position, it is copied to the output string (except non-significant zeros) ; Section separator: if there is one section in the format string, it applies to all values. If there are two sections, the first applies to positive values and to zeros and the second applies to negative values. If there are three sections, the first applies to positive values, the second to negative values and the third to zeros, except if the second section is empty, in which case the first section applies to all non-negative values. Everything in enclosed by ' or " in the format string will be copied to the output as is. I've been looking for a (C++) solution for this for a long time and as I didn't find anything appropriate, I developed it myself finally. If anybody is interested, I could post source somewhere. Stefan

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