- Boost-users - lists.preview.boost.org

[variant] is_a/can_be
by Yuval Ronen 05 Feb '05

05 Feb '05

Hi. I encountered the need to query a boost::variant to which type it currently contain. I'm talking about something like: variant<int, string> v(3); assert(v.is_a<int>()); assert(!v.is_a<string>()); This can be done using the which() method, but its drawback is that I rely on the order of the types in the variant declaration rather on the type, which is really what I'm interested in. I can implement the variant_is_a<>() feature using a visitor such as: template &… [View More]

4 7

RE: [Boost-users] Re: Bug in boost::lambda using operator <<?
by Richard_Cox＠Dell.com 05 Feb '05

05 Feb '05

On Friday, February 04, 2005 5:47 PM Kevin Wheatley wrote: > > Richard_Cox(a)Dell.com wrote: > > > > The program below outputs > > > > String: <First string> Second string> Fourth string> Fifth string> > > > > All but the first "<" is missing. Any ideas? > > std::for_each(coll.begin(), coll.end(), out << gt << _1 > << L"> "); > > > does this work? > > std::for_each(coll.begin(),… [View More]

1 0

implementing an iterator
by Chris Goller 04 Feb '05

04 Feb '05

I'm using iterator_facade to implement an iterator over file based data. So, my question is, since deference returns a reference to a value does that reference need to persist when the iterator is incremented or decremented? Because this is file based data I can't always keep a reference around because the data is stored on disk. Thanks, Chris

2 1

boost::function as drop-in replacment for ordinary function pointers?
by Oliver Kowalke 04 Feb '05

04 Feb '05

Hi, is it possible to use boost::function as drop-in replacment for ordinary function pointers - or are there some other solutions? I can't get the code below to work. thx and best regards, Oliver typedef void (*FunctionPointer) ( int); void my_fun( int i) { std::cout << i << std::endl; } class MyFun { public: void operator()( int i) { std::cout << i << std::endl; } }; class Test { public: void f( FunctionPointer fp) { fp( 1); } }; void main() { Test tst; … [View More]

2 1

Bug in boost::lambda using operator <<?
by Richard_Cox＠Dell.com 04 Feb '05

04 Feb '05

The program below outputs String: <First string> Second string> Fourth string> Fifth string> All but the first "<" is missing. Any ideas? (On vc++7.1 using Boost 1.32.0.) Richard All opinions are mine and do not represent in any way the position of Dell Corporation. #include <ostream> #include <iostream> #include <string> #include <vector> #include <algorithm> #include <boost/lambda/lambda.hpp> using std::wstring; using std::wcout;… [View More]

2 1

Use of dollar signs in variable names when using boost::archive::xml_iarchive
by lloyd.reed＠leica-microsystems.com 04 Feb '05

04 Feb '05

I have found a bug or undocumented limitation in the boost serialization library. I'm using VC++ 2003, which allows you to use variable names which include dollar signs ($). Variables with names containing dollar signs can be saved to an archive using the boost::archive::xml_oarchive class. When boost::archive::xml_iarchive is used to reload the variable, however, the parsing of the variable name fails, and basic_xml_iarchive<Archive>::load_start(const char *name) calls boost::… [View More]

2 2

shared_ptr on HP-UX - patch
by Jaroslav Gresula 04 Feb '05

04 Feb '05

I tried to compile the smart pointer regression tests on HP-UX and found out that the compiler takes the 'advanced' version of get_deleter() template function (defined in shared_ptr.hpp) which is evidently beyond its limits (we use aCC, version HP ANSI C++ B3910B A.03.35). In case anyone is interested, I attached a 'patch' against shared_ptr.hpp, revision 1.52 - it just redirects the compiler to the already existing workaround version. /Jarda *** shared_ptr.hpp.orig Wed Feb 2 22:12:50 … [View More]

3 2

weak_ptr_test - non-portable?
by Jaroslav Gresula 04 Feb '05

04 Feb '05

When I run the weak_ptr_test (a part of the regression tests) on HP-UX (aCC version HP ANSI C++ B3910B A.03.35) I'm getting a lot of failures. The reason is that IMHO the weak_ptr_test.cpp relies on a non-portable construct. There is copy_assignment() template function which takes shared_ptr<> by value. All caller sites of this function pass on an unnamed shared_ptr<> temporary. The first line of copy_assignment() checks if shared_ptr<>::unique() is true for the passed … [View More]

2 1

Installation log
by Nicolas Busca 04 Feb '05

04 Feb '05

Hi! Is there any way to see the installation log of boost? When I installed it I got a message in the end that ~50 out of ~1000 links failed to be created. How could I know which they were? Thanks, Nicolas Busca.

2 1

BGL + SubGraph + Remove
by Gordon Smith 04 Feb '05

04 Feb '05

Is there anyway to remove a subgraph once created? Gordon.

1 0