January 2002 - Boost-users - lists.preview.boost.org

Another Bind Question
by Duane Murphy 04 Jan '02

04 Jan '02

Bind has been working very well for some of the things I have been wanting to do. I have run into a rather puzzling problem this time and was wondering what was happening: Here is the example: void f( int ) { } struct array_obj { int operator[]( int ){ return NULL; } }; int main() { array_obj a; int array[1]; int value = a[0]; boost::bind( f, _1 )( 3 ); boost::bind( f, _1 )( value ); boost::bind( f, _1 )( array[0] ); boost::bind( f, _1 )( a[0] ); return 0; } The first three bind statements compile just fine. The third one issues an error: function call 'operator()(int)' does not match. Along with all 20 variations of operator() generated by bind. Obviously there is something amiss with going through the return value of operator[](). I also get the same problem using an iterator which would be going through operator*(). I am using CodeWarrior 7 on Mac on OS X. Could this be a compiler specific problem? I can work around the problem using bind1st but it seems odd that bind1st works and bind doesnt? Could CW have included some magic in bind1st to work around this? Thanks for the help, ..Duane

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Using boost::thread under Visual C++
by John Maddock 03 Jan '02

03 Jan '02

>I'm still flummoxed. If you have more ideas, I would really appreciate >them. Why not just use your IDE to build threadmon.cpp as a dll, and the rest of the source as a static lib, using whatever your project options are? - John Maddock http://ourworld.compuserve.com/homepages/john_maddock/

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iterator_adaptors on Tru64 version V6.1-027
by vvasta 02 Jan '02

02 Jan '02

Hi all, I'm trying to use the iterator_adaptors class on Tru64. To make it work I had to do the following changes: In concept_check.hpp I had to change the code from this: template <class Concept> inline void function_requires() { #if !defined(NDEBUG) void (Concept::*x)() = BOOST_FPTR Concept::constraints; ignore_unused_variable_warning(x); #endif } to this: template <class Concept> inline void function_requires(type<Concept> t = type<Concept>()) { #if !defined(NDEBUG) void (Concept::*x)() = BOOST_FPTR Concept::constraints; ignore_unused_variable_warning(x); #endif } because this compiler generates an error if a template parameter is not used in the function declaration. In iterator_adaptors.hpp I had to remove the parenthesis around all the if_true bool template parameter from this: typedef typename if_true<( // original version ::boost::is_same<Value,typename iterator_traits<Iterator>::value_type>::value )>::template then< typename iterator_traits<Iterator>::pointer, Value* >::type pointer; to this: typedef typename if_true< // Changed version no parenthesis ::boost::is_same<Value,typename iterator_traits<Iterator>::value_type>::value >::template then< typename iterator_traits<Iterator>::pointer, Value* >::type pointer; It is possible to put this changes in the original distribution in order to avoid to put this changes in any new boost release I use ? Thanks for your help Vincenzo

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