How does this work? I'm trying to use the make_transform_iterator to make a writeable output iterator (looks like it is referred to as a "Writeable LValue" in the iterator template code), but I can't figure out how to do it. Here's the example: (I know that I could have used the make_transform_iterators on the source iterators in this toy example, but that won't do for my real application) typedef map Map; typedef vector<int> V1; typedef vector<string> V2; string convert(int iValue) { return str(ostringstream() << iValue); } int _tmain(int argc, _TCHAR* argv[]) { V1 aSourceVector; V2 aTargetVector; copy(aSourceVector.begin(), aSourceVector.end(), make_transform_iterator(back_inserter(aTargetVector), boost::bind(convert, _1)); } The compiler (MSVC 7.1.3008) generates a compile errors like at the end of this message. Anybody know the right way to do this? Can you use an iterator adaptor as an output iterator, or is this wishful thinking on my part? Rob. Compiling... make_transform_iterator.cpp d:\scratch\make_transform_iterator\make_transform_iterator.cpp(20) : error C2514: 'std::basic_ostringstream<_Elem,_Traits,_Alloc>' : class has no constructors with [ _Elem=char, _Traits=std::char_traits<char>, _Alloc=std::allocator<char> ] d:\scratch\make_transform_iterator\make_transform_iterator.cpp(20) : see reference to class template instantiation 'std::basic_ostringstream<_Elem,_Traits,_Alloc>' being compiled with [ _Elem=char, _Traits=std::char_traits<char>, _Alloc=std::allocator<char> ] d:\scratch\make_transform_iterator\make_transform_iterator.cpp(20) : error C3861: 'str': identifier not found, even with argument-dependent lookup d:\svn\code\thirdpty\boost\boost_1.32.0\boost\iterator\iterator_facade.hpp(6 52) : error C2182: 'n' : illegal use of type 'void' d:\svn\code\thirdpty\boost\boost_1.32.0\boost\iterator\iterator_adaptor.hpp( 266) : see reference to class template instantiation 'boost::iterator_facade' being compiled with [ Derived=boost::transform_iterator>::B1>>,std::ba ck_insert_iterator<V2>,boost::use_default,boost::use_default>, Value=boost::mpl::identity>::B1>>,std::ba ck_insert_iterator<V2>,boost::use_default,boost::use_default>::cv_value_type

::type,

CategoryOrTraversal=boost::mpl::identityboost::incrementable_traversal_tag ::type, Reference=boost::mpl::identity>::B1>>,std::ba ck_insert_iterator<V2>,boost::use_default,boost::use_default>::cv_value_type

::type,

Difference=boost::iterator_difference::type ] d:\svn\code\thirdpty\boost\boost_1.32.0\boost\iterator\transform_iterator.hp p(92) : see reference to class template instantiation 'boost::iterator_adaptor' being compiled with [ Derived=boost::transform_iterator>::B1>>,std::ba ck_insert_iterator<V2>,boost::use_default,boost::use_default>, Base=std::back_insert_iterator<V2>, Value=boost::detail::transform_iterator_base>::B1>>,std::ba ck_insert_iterator<V2>,boost::use_default,boost::use_default>::cv_value_type , Traversal=boost::use_default, Reference=boost::detail::transform_iterator_base>::B1>>,std::ba ck_insert_iterator<V2>,boost::use_default,boost::use_default>::reference ] d:\scratch\make_transform_iterator\make_transform_iterator.cpp(28) : see reference to class template instantiation 'boost::transform_iterator' being compiled with [ UnaryFunction=boost::_bi::bind_t>::B1>>, Iterator=std::back_insert_iterator<V2>, Reference=boost::use_default, Value=boost::use_default ] d:\svn\code\thirdpty\boost\boost_1.32.0\boost\iterator\iterator_facade.hpp(6 92) : error C2182: 'n' : illegal use of type 'void' d:\svn\code\thirdpty\boost\boost_1.32.0\boost\iterator\iterator_facade.hpp(6 98) : error C2182: 'n' : illegal use of type 'void' d:\svn\code\thirdpty\boost\boost_1.32.0\boost\iterator\iterator_facade.hpp(7 04) : error C2182: 'x' : illegal use of type 'void' d:\svn\code\thirdpty\boost\boost_1.32.0\boost\iterator\iterator_adaptor.hpp( 326) : error C2182: 'n' : illegal use of type 'void' d:\scratch\make_transform_iterator\make_transform_iterator.cpp(28) : error C2143: syntax error : missing ')' before ';' Build log was saved at "file://d:\scratch\make_transform_iterator\Debug\BuildLog.htm" make_transform_iterator - 8 error(s), 0 warning(s)