June 2010 - Boost-users - lists.boost.org

[MultiIndex] As if one iterator
by Dan Bloomquist 11 Jun '10

11 Jun '10

I have a muti_index for a database. First I'll say, this will be so much better than my old way of running an SQL every time I wanted to change the order. Thanks. I never see a database bigger than some 1200 records, usually <200, so I'm not worried about memory bloat. So I've wrapped the multi_index in a class that will hide the boost includes from the rest of my app. I'll include the work below. I'd like to treat some kind of interface, like a generic iterator, depending on what order I have set. I would only use one iterator at a time. But the iterators are templated and have no base so that I can easily keep a set of iterators handy, say in a container, and then supply the appropriate iterator through an interface. In my class, RaOrderRecords, I'd something like: set.GetIt( ) set.IncIt( ) set.IsEndIt( ) etc. Or even overload so I could set++ And a member like SetOrder( [enum of new order] ) to have the internal iterator switched. I'm sure there is an elegant way to deal with this, but it escapes me. Thanks, Dan. ~~~~~ .hpp #pragma once // // ............................................................ namespace RsOrderIndex { struct ord_key{ }; struct ord_id{ }; struct ord_desc{ }; struct ord_sevice{ }; struct ord_remain{ }; struct ord_cat{ }; struct ord_group{ }; enum RecOrderIndex { ordNull, ordKey, ordId, ordDesc, ordService, ordRemain, ordCat, ordGroup, }; }; // ............................................................ class RaOrderRecords; struct ord_record_item { //properties RaOrderRecords* pParent; size_t absPos; //indexed properties long key; std::string strId; std::string strDescription; COleDateTime dtInService; long remaining; long catKey; long groupKey; //one and only constructor ord_record_item( RaOrderRecords *pInParent, long inKey, CString& inId, CString& inDesc, COleDateTime& indtIns, long inRemain, long inCatKey, long inGroupKey, size_t inPos ) :pParent( pInParent ) ,key( inKey ) ,strId( inId ) ,strDescription( inDesc ) ,dtInService( indtIns ) ,remaining( inRemain ) ,catKey( inCatKey ) ,groupKey( inGroupKey ) ,absPos( inPos ) { } //useful members size_t GetAbsPos( ) const { return absPos; } //indexing members bool operator < ( const ord_record_item& e ) const { return key < e.key; } unsigned long cat_pos( ) const; unsigned long group_pos( ) const; }; // ............................................................ #ifdef INCLUDE_ORDRECORD_BASE //to isolate boost headers typedef boost::multi_index::multi_index_container < ord_record_item, boost::multi_index::indexed_by < // sort by primary database key, ord_record_item comp boost::multi_index::ordered_unique < boost::multi_index::tag< RsOrderIndex::ord_key >, boost::multi_index::identity< ord_record_item > >, // sort by less<string> on strId boost::multi_index::ordered_non_unique < boost::multi_index::tag< RsOrderIndex::ord_id >, BOOST_MULTI_INDEX_MEMBER( ord_record_item, std::string, strId ) >, // sort by less<string> on strDescription boost::multi_index::ordered_non_unique < boost::multi_index::tag< RsOrderIndex::ord_desc >, BOOST_MULTI_INDEX_MEMBER( ord_record_item, std::string, strDescription ) >, // sort by less<COleDateTime> on dtInService boost::multi_index::ordered_non_unique < boost::multi_index::tag< RsOrderIndex::ord_sevice >, BOOST_MULTI_INDEX_MEMBER( ord_record_item, COleDateTime, dtInService ) >, // sort by less<COleDateTime> on remaining, Description boost::multi_index::ordered_non_unique < boost::multi_index::tag< RsOrderIndex::ord_remain >, boost::multi_index::composite_key < ord_record_item, BOOST_MULTI_INDEX_MEMBER( ord_record_item, long, remaining ), BOOST_MULTI_INDEX_MEMBER( ord_record_item, std::string, strDescription ) > >, // sort by category, description boost::multi_index::ordered_non_unique < boost::multi_index::tag< RsOrderIndex::ord_cat >, boost::multi_index::composite_key < ord_record_item, BOOST_MULTI_INDEX_CONST_MEM_FUN( ord_record_item, unsigned long, cat_pos ), BOOST_MULTI_INDEX_MEMBER( ord_record_item, std::string, strDescription ) > >, // sort by group, description boost::multi_index::ordered_non_unique < boost::multi_index::tag< RsOrderIndex::ord_group >, boost::multi_index::composite_key < ord_record_item, BOOST_MULTI_INDEX_CONST_MEM_FUN( ord_record_item, unsigned long, group_pos ), BOOST_MULTI_INDEX_MEMBER( ord_record_item, std::string, strDescription ) > > > >ord_record_set; typedef ord_record_set::index< RsOrderIndex::ord_key >::type::iterator It_key_ord; typedef ord_record_set::index< RsOrderIndex::ord_id >::type::iterator It_id_ord; typedef ord_record_set::index< RsOrderIndex::ord_desc >::type::iterator It_desc_ord; typedef ord_record_set::index< RsOrderIndex::ord_sevice >::type::iterator It_service_ord; typedef ord_record_set::index< RsOrderIndex::ord_remain >::type::iterator It_remain_ord; typedef ord_record_set::index< RsOrderIndex::ord_cat >::type::iterator It_cat_ord; typedef ord_record_set::index< RsOrderIndex::ord_group >::type::iterator It_group_ord; nth_index_iterator #else // INCLUDE_ORDRECORD_BASE //forward declared for general use, no multi record boost headers class ord_record_set; #endif // INCLUDE_ORDRECORD_BASE // ............................................................ class RaOrderRecords { ord_record_set* pOrder; RaCatGroupMap catSet; RaCatGroupMap groupSet; //RSKeyPosSet keyPosSet; public: RaOrderRecords( ); ~RaOrderRecords( ); bool ReadRecordSet( RaRecordset* pRS ); unsigned long GetCatPos( long inCatKey ) { RaCatGroupMapIt it= catSet.find( inCatKey ); if( it != catSet.end( ) ) return it->second.ordered; else return -1;//max unsigned } unsigned long GetGroupPos( long inGroupKey ) { RaCatGroupMapIt it= groupSet.find( inGroupKey ); if( it != groupSet.end( ) ) return it->second.ordered; else return -1;//max unsigned } #ifdef _DEBUG void Dump( RsOrderIndex::RecOrderIndex index ); #else void Dump( RsOrderIndex::RecOrderIndex index ) { } #endif }; ~~~~~~.cpp #include "stdafx.h" #if !defined(NDEBUG) #include <boost/multi_index/safe_mode_errors.hpp> #define BOOST_MULTI_INDEX_ENABLE_INVARIANT_CHECKING #define BOOST_MULTI_INDEX_ENABLE_SAFE_MODE #endif #include <boost/multi_index_container.hpp> #include <boost/multi_index/ordered_index.hpp> #include <boost/multi_index/identity.hpp> #include <boost/multi_index/member.hpp> #include <boost/multi_index/mem_fun.hpp> #include <boost/multi_index/composite_key.hpp> #include "records.h" #define INCLUDE_ORDRECORD_BASE #include "RecordsOrd.hpp" // ......................................................... using namespace boost::multi_index; using namespace RsOrderIndex; unsigned long ord_record_item::cat_pos( ) const { return pParent->GetCatPos( catKey ); } unsigned long ord_record_item::group_pos( ) const { return pParent->GetGroupPos( groupKey ); } RaOrderRecords::RaOrderRecords( ) { pOrder= new ord_record_set; } RaOrderRecords::~RaOrderRecords( ) { delete pOrder; } bool RaOrderRecords::ReadRecordSet( RaRecordset* pRS ) { pOrder->clear( ); LoadCategories( catSet ); LoadGroups( groupSet ); COleDateTime dtNo( 10000.0 );// TODO !!!! try { int i= 1; for( pRS->MoveFirst( ); ! pRS->IsEOF( ); pRS->MoveNext( ) ) { pOrder->insert( ord_record_item( this, pRS->ds_id, pRS->ds_number, pRS->ds_description, pRS->IsFieldNull( &pRS->ds_inService ) ? dtNo : pRS->ds_inService, pRS->GetRemaining( ), pRS->ds_catKey, pRS->ds_groupKey, i ) ); // keyPosSet.SetKeyPos( pRS->ds_id, i++ ); } } catch( CDBException* e ) { e->Delete( ); return false; } return true; } #ifdef _DEBUG void RaOrderRecords::Dump( RecOrderIndex index ) { std::string strT; strT.c_str( ); It_cat_ord it= pOrder->get< ord_cat >( ).begin( ); for( int i= 1; it != pOrder->get< ord_cat >( ).end( ); ++it, ++i ) { CString strT; RaCatGroupMapIt cat= catSet.find( it->catKey ); if( cat != catSet.end( ) ) strT= cat->second.title; else strT= _T("(null)"); TRACE( "%3.0d %s---%s\n", i, strT, it->strDescription.c_str( ) ); } //It_service_ord sit= pOrder->get< ord_sevice >( ).begin( ); //for( ; sit != pOrder->get< ord_sevice >( ).end( ); ++sit ) // TRACE( "%s---%s\n", sit->strDescription.c_str( ), sit->dtInService.Format( _T("%m/%d/%y") ) ); } #endif //_DEBUG

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[Filesystem] create dir tree
by John Dlugosz 11 Jun '10

11 Jun '10

In the past, I've used a function like "assure_path_exists" which will create it if necessary, multiple levels deep if the parent(s) don't already exist. Does the creation function in this library create intermediate directories? The docs are not clear. I also want to efficiently and silently accept the case where the directory already exists. Does the creation function do that (how to tell real errors?), or do I need to check first? --John TradeStation Group, Inc. is a publicly-traded holding company (NASDAQ GS: TRAD) of three operating subsidiaries, TradeStation Securities, Inc. (Member NYSE, FINRA, SIPC and NFA), TradeStation Technologies, Inc., a trading software and subscription company, and TradeStation Europe Limited, a United Kingdom, FSA-authorized introducing brokerage firm. None of these companies provides trading or investment advice, recommendations or endorsements of any kind. The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender and delete the material from any computer.

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Filesystem question
by John Dlugosz 11 Jun '10

11 Jun '10

Is there a function in the filesystem (TR2 proposal) that will take one path and return the fully qualified form? That is, what it resolves to now, applying any current-working-directory concepts. The Win32 API function I'm using now (with plain strings) is GetFullPathName. --John TradeStation Group, Inc. is a publicly-traded holding company (NASDAQ GS: TRAD) of three operating subsidiaries, TradeStation Securities, Inc. (Member NYSE, FINRA, SIPC and NFA), TradeStation Technologies, Inc., a trading software and subscription company, and TradeStation Europe Limited, a United Kingdom, FSA-authorized introducing brokerage firm. None of these companies provides trading or investment advice, recommendations or endorsements of any kind. The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender and delete the material from any computer.

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[Filesystem] remove (p,ec);
by John Dlugosz 10 Jun '10

10 Jun '10

I call remove (p,ec); and get a compile-time error that no form takes two arguments. Looking in the header, that seems to be the case. The Filesystem Reference (<http://www.boost.org/doc/libs/1_43_0/libs/filesystem/doc/reference.html>) clearly shows an error code parameter. I understand this module is tracking the standardization process. So which is newer? Should I be anticipating the code change to match the docs, or vice versa? How do I find out if there was an error and report the details? Note that I want to consider the case of the file not existing in the first place as OK. --John TradeStation Group, Inc. is a publicly-traded holding company (NASDAQ GS: TRAD) of three operating subsidiaries, TradeStation Securities, Inc. (Member NYSE, FINRA, SIPC and NFA), TradeStation Technologies, Inc., a trading software and subscription company, and TradeStation Europe Limited, a United Kingdom, FSA-authorized introducing brokerage firm. None of these companies provides trading or investment advice, recommendations or endorsements of any kind. The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender and delete the material from any computer.

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[Filesystem] what is 'singular'?
by John Dlugosz 10 Jun '10

10 Jun '10

template <class Path> bool remove(const Path& p, system::error_code & ec = singular ); * if ec != singular, then ec.clear(). I can't find any definition for 'singular'. What is it? Besides acting as a flag to know if the argument was defaulted, it seems like it's doing some kind of one-shot behavior? --John TradeStation Group, Inc. is a publicly-traded holding company (NASDAQ GS: TRAD) of three operating subsidiaries, TradeStation Securities, Inc. (Member NYSE, FINRA, SIPC and NFA), TradeStation Technologies, Inc., a trading software and subscription company, and TradeStation Europe Limited, a United Kingdom, FSA-authorized introducing brokerage firm. None of these companies provides trading or investment advice, recommendations or endorsements of any kind. The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender and delete the material from any computer.

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Filesystem Path question
by John Dlugosz 10 Jun '10

10 Jun '10

The basic_path constructor that takes two InputIterators: what kind of iterator is that? It doesn't seem to want characters, but an iterator of parts like produced by the begin/end functions. But the iterator's underlying type is not defined, so you can't make your own collection of "parts". So why doesn't the constructor just take its own iterator type, but is a template? What else could you give it? The documentation is not clear. --John TradeStation Group, Inc. is a publicly-traded holding company (NASDAQ GS: TRAD) of three operating subsidiaries, TradeStation Securities, Inc. (Member NYSE, FINRA, SIPC and NFA), TradeStation Technologies, Inc., a trading software and subscription company, and TradeStation Europe Limited, a United Kingdom, FSA-authorized introducing brokerage firm. None of these companies provides trading or investment advice, recommendations or endorsements of any kind. The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender and delete the material from any computer.

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bz2 & gzip support - ld can't find symboles
by Kraus Philipp 10 Jun '10

10 Jun '10

Hi, I try to use the bz2 and gzip iostreams from Boost 1.43 on my OSX Snow Leopard. The code is compiled without any errors, but the ld returns: Undefined symbols: "boost::iostreams::detail::zlib_base::do_init(boost::iostreams::zlib_params const&, bool, void* (*)(void*, unsigned int, unsigned int), void (*)(void*, void*), void*)", referenced from: boost::iostreams::detail::zlib_compressor_impl<std::allocator<char> >::zlib_compressor_impl(boost::iostreams::zlib_params const&)in ncd.o [...] I had setup the -l G++ option to "z" and "bz2" but I can't link my code. I had compiled the Boost from sources with bjam -sHAVE_ICU=1 -sZLIB_BINARY -sBZIP2_BINARY --with-mpi toolset=darwin install --prefix= Binaries for the zip algorithms are under /usr/lib After compiling with bjam I get 4 libs: libbost_mpi.dylib, libbost_serialization.dylib and both as *.a files. Do I have forget anything on compile / link option? I had found an articel for Windows in which bjam should create some boost zip libraries. I try the example on http://www.boost.org/doc/libs/1_43_0/libs/iostreams/doc/classes/zlib.html#i… but it run into errors. Thanks for help Phil

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Program Options and utf8_codecvt_facet.hpp
by John Dlugosz 10 Jun '10

10 Jun '10

The Program Options library source includes the common utf8_codecvt_facet stuff. But, I don't see any use of it. Why is it in this lib/dll? --John TradeStation Group, Inc. is a publicly-traded holding company (NASDAQ GS: TRAD) of three operating subsidiaries, TradeStation Securities, Inc. (Member NYSE, FINRA, SIPC and NFA), TradeStation Technologies, Inc., a trading software and subscription company, and TradeStation Europe Limited, a United Kingdom, FSA-authorized introducing brokerage firm. None of these companies provides trading or investment advice, recommendations or endorsements of any kind. The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender and delete the material from any computer.

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[proto] Matching grammars in the presence of adapted types
by Sebastian Redl 10 Jun '10

10 Jun '10

Hi, First off, this whole thing uses Boost 1.42. I'm trying to define arithmetic types where some expression patterns will be matched and replaced by something else (e.g. a & ~b, the andnot pattern). The whole thing is a proof-of-concept and teach-myself-proto thing that should eventually do SIMD operations. Right now, though, it simply wraps integers. First I tried defining my type as a proto type this way: ----------------- template <typename Expr> class simd_expr : public proto::extends<Expr, simd_expr<Expr>, simd_domain> { /* as in the tutorial */ }; class smartint : public simd_expr<proto::terminal<smartint>::type> { int value; // ... }; inline smartint ilit(int i) { return smartint(i); } ----------------- However, this didn't work, because at the instantiation point of simd_expr<proto::terminal<smartint>::type>, smartint is incomplete, and something in proto doesn't like that. So I used the only thing in the docs that looked like my use case, and did the non-intrusive adapting thing demonstrated on the matrix and vector classes. ----------------- class smartint { ... }; template <typename T> struct is_terminal : mpl::false_ {}; template <> struct is_terminal<smartint> : mpl::true_ {}; BOOST_PROTO_DEFINE_OPERATORS(is_terminal, simd_domain) ----------------- This works nicely for normal evaluations. I have a simd_context, which knows how to evaluate smartint, and forwards everything else to default_context: ----------------- struct simd_context : proto::callable_context<simd_context const, proto::default_context> { typedef int result_type; int operator ()(proto::tag::terminal, smartint const &si) const; }; inline int simd_context::operator ()( proto::tag::terminal, smartint const &si) const { return si.get(); } ----------------- Now I can do fun stuff like this: ----------------- int i = ilit(7) + 3; // simd_expr has 'operator int' ----------------- Now I want to match specific expression patterns and do something special for them. For example, in this expression: ----------------- i = 1 * (0xF0 & ~ilit(0x70)); ----------------- I want to match the 'a & ~b' pattern and treat it specially. So first, I define this pattern as a grammar: ----------------- struct andnot_pattern : proto::bitwise_and<proto::_, proto::complement<proto::_>> {}; ----------------- And then I add another function to my context that applies only to expressions matching this pattern: ----------------- template <typename Tag, typename Expr> typename boost::enable_if< proto::matches<Expr, andnot_pattern>, int>::type operator ()(Tag, Expr const &e) const { std::cerr << "Found andnot pattern\n"; return 0xFF; } ----------------- However, when I try to compile this, VC++ 2010 complains: boost_1_42_0\boost\proto\matches.hpp(502): error C2039: 'proto_base_expr' : is not a member of 'smart::smartint' Pointing here: ----------------- template<typename Expr, typename Grammar> struct matches : detail::matches_< typename Expr::proto_base_expr , typename Grammar::proto_base_expr > {}; ----------------- So apparently, while callable_context is trying to find an appropriate overload for some stuff, it tries out my template operator, passing a smartint as Expr, and matches<> can't handle adapted types. Because the error is within matches<>, it's not SFINAEable and the compiler errors out instead of eliminating the function. What can I do? Can I teach matches<> to handle adapted types? Is there a "right" way to implement smartint so that it needn't be an adapted type, which would work around the whole issue? Is this a bug in Proto that is fixed in trunk, or can be fixed? Sebastian

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Testing private methods in Boost
by hmiller＠hiwaay.net 10 Jun '10

10 Jun '10

Is their a good strategy for testing private methods in a class using Boost? I am looking for something that is non-intrusive to the developed code, but I can't think of any good ways without modifying the code under test. Thanks, Herb Miller

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