C++ 超载>&燃气轮机；ifstream\u成对迭代器

我试图在pair上构造一个ifstream_迭代器。我的代码如下：

typedef pair<float, int> T;

istream& operator>>(istream& stream, T& in) {
    stream >> in.first >> in.second;
    return stream;
}


int main(int argc, char **argv) {
    ifstream infile("dummy2");
    istream_iterator<T> iit(infile);
    istream_iterator<T> eos;
    while (iit != eos) {
        cout << (*iit).first << endl;
        ++iit;
    }
    return 0;
}

"a" 4 "b" 5

我想输出对{“a”，4}和{“b”，5}

然而，我遇到了严重的编译错误

In file included from /usr/include/c++/4.6/iterator:66:0,
                 from filestream.cpp:9:
/usr/include/c++/4.6/bits/stream_iterator.h: In member function ‘void std::istream_iterator<_Tp, _CharT, _Traits, _Dist>::_M_read() [with _Tp = std::pair<float, int>, _CharT = char, _Traits = std::char_traits<char>, _Dist = long int]’:
/usr/include/c++/4.6/bits/stream_iterator.h:70:9:   instantiated from ‘std::istream_iterator<_Tp, _CharT, _Traits, _Dist>::istream_iterator(std::istream_iterator<_Tp, _CharT, _Traits, _Dist>::istream_type&) [with _Tp = std::pair<float, int>, _CharT = char, _Traits = std::char_traits<char>, _Dist = long int, std::istream_iterator<_Tp, _CharT, _Traits, _Dist>::istream_type = std::basic_istream<char>]’
filestream.cpp:32:33:   instantiated from here
/usr/include/c++/4.6/bits/stream_iterator.h:121:6: error: no match for ‘operator>>’ in ‘*((std::istream_iterator<std::pair<float, int> >*)this)->std::istream_iterator<std::pair<float, int> >::_M_stream >> ((std::istream_iterator<std::pair<float, int> >*)this)->std::istream_iterator<std::pair<float, int> >::_M_value’
/usr/include/c++/4.6/bits/stream_iterator.h:121:6: note: candidates are:
/usr/include/c++/4.6/istream:122:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__istream_type& (*)(std::basic_istream<_CharT, _Traits>::__istream_type&)) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/usr/include/c++/4.6/istream:122:7: note:   no known conversion for argument 1 from ‘std::pair<float, int>’ to ‘std::basic_istream<char>::__istream_type& (*)(std::basic_istream<char>::__istream_type&) {aka std::basic_istream<char>& (*)(std::basic_istream<char>&)}’
/usr/include/c++/4.6/istream:126:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__ios_type& (*)(std::basic_istream<_CharT, _Traits>::__ios_type&)) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>, std::basic_istream<_CharT, _Traits>::__ios_type = std::basic_ios<char>]
/usr/include/c++/4.6/istream:126:7: note:   no known conversion for argument 1 from ‘std::pair<float, int>’ to ‘std::basic_istream<char>::__ios_type& (*)(std::basic_istream<char>::__ios_type&) {aka std::basic_ios<char>& (*)(std::basic_ios<char>&)}’
/usr/include/c++/4.6/istream:133:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(std::ios_base& (*)(std::ios_base&)) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/usr/include/c++/4.6/istream:133:7: note:   no known conversion for argument 1 from ‘std::pair<float, int>’ to ‘std::ios_base& (*)(std::ios_base&)’
/usr/include/c++/4.6/istream:169:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(bool&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/usr/include/c++/4.6/istream:169:7: note:   no known conversion for argument 1 from ‘std::pair<float, int>’ to ‘bool&’
/usr/include/c++/4.6/istream:173:7: note: std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(short int&) [with _CharT = char, _Traits = std::char_traits<char>]
/usr/include/c++/4.6/istream:173:7: note:   no known conversion for argument 1 from ‘std::pair<float, int>’ to ‘short int&’
/usr/include/c++/4.6/istream:176:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(short unsigned int&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/usr/include/c++/4.6/istream:176:7: note:   no known conversion for argument 1 from ‘std::pair<float, int>’ to ‘short unsigned int&’
/usr/include/c++/4.6/istream:180:7: note: std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(int&) [with _CharT = char, _Traits = std::char_traits<char>]
/usr/include/c++/4.6/istream:180:7: note:   no known conversion for argument 1 from ‘std::pair<float, int>’ to ‘int&’
/usr/include/c++/4.6/istream:183:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(unsigned int&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/usr/include/c++/4.6/istream:183:7: note:   no known conversion for argument 1 from ‘std::pair<float, int>’ to ‘unsigned int&’
/usr/include/c++/4.6/istream:187:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long int&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/usr/include/c++/4.6/istream:187:7: note:   no known conversion for argument 1 from ‘std::pair<float, int>’ to ‘long int&’
/usr/include/c++/4.6/istream:191:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long unsigned int&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/usr/include/c++/4.6/istream:191:7: note:   no known conversion for argument 1 from ‘std::pair<float, int>’ to ‘long unsigned int&’
/usr/include/c++/4.6/istream:196:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long int&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/usr/include/c++/4.6/istream:196:7: note:   no known conversion for argument 1 from ‘std::pair<float, int>’ to ‘long long int&’
/usr/include/c++/4.6/istream:200:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long unsigned int&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/usr/include/c++/4.6/istream:200:7: note:   no known conversion for argument 1 from ‘std::pair<float, int>’ to ‘long long unsigned int&’
/usr/include/c++/4.6/istream:205:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(float&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/usr/include/c++/4.6/istream:205:7: note:   no known conversion for argument 1 from ‘std::pair<float, int>’ to ‘float&’
/usr/include/c++/4.6/istream:209:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(double&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/usr/include/c++/4.6/istream:209:7: note:   no known conversion for argument 1 from ‘std::pair<float, int>’ to ‘double&’
/usr/include/c++/4.6/istream:213:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long double&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/usr/include/c++/4.6/istream:213:7: note:   no known conversion for argument 1 from ‘std::pair<float, int>’ to ‘long double&’
/usr/include/c++/4.6/istream:217:7: note: std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(void*&) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]
/usr/include/c++/4.6/istream:217:7: note:   no known conversion for argument 1 from ‘std::pair<float, int>’ to ‘void*&’
/usr/include/c++/4.6/istream:241:7: note: std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(std::basic_istream<_CharT, _Traits>::__streambuf_type*) [with _CharT = char, _Traits = std::char_traits<char>, std::basic_istream<_CharT, _Traits>::__streambuf_type = std::basic_streambuf<char>]
/usr/include/c++/4.6/istream:241:7: note:   no known conversion for argument 1 from ‘std::pair<float, int>’ to ‘std::basic_istream<char>::__streambuf_type* {aka std::basic_streambuf<char>*}’
/usr/include/c++/4.6/bits/basic_string.tcc:998:5: note: template<class _CharT, class _Traits, class _Alloc> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::basic_string<_CharT, _Traits, _Alloc>&)
/usr/include/c++/4.6/bits/random.tcc:923:5: note: template<class _IntType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::uniform_int_distribution<_IntType>&)
/usr/include/c++/4.6/bits/random.tcc:968:5: note: template<class _RealType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::uniform_real_distribution<_RealType>&)
/usr/include/c++/4.6/bits/random.tcc:1890:5: note: template<class _RealType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::cauchy_distribution<_RealType>&)
/usr/include/c++/4.6/bits/random.h:3381:5: note: template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::bernoulli_distribution&)
/usr/include/c++/4.6/bits/random.tcc:1733:5: note: template<class _RealType1, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::normal_distribution<_RealType1>&)
/usr/include/c++/4.6/bits/random.tcc:1063:5: note: template<class _IntType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::geometric_distribution<_IntType>&)
/usr/include/c++/4.6/bits/random.tcc:2085:5: note: template<class _RealType1, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::gamma_distribution<_RealType1>&)
/usr/include/c++/4.6/bits/random.tcc:1622:5: note: template<class _RealType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::exponential_distribution<_RealType>&)
/usr/include/c++/4.6/bits/random.tcc:2143:5: note: template<class _RealType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::weibull_distribution<_RealType>&)
/usr/include/c++/4.6/bits/random.tcc:2200:5: note: template<class _RealType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::extreme_value_distribution<_RealType>&)
/usr/include/c++/4.6/bits/random.tcc:194:5: note: template<class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::linear_congruential_engine<_UIntType, __a, __c, __m>&)
/usr/include/c++/4.6/bits/random.tcc:491:5: note: template<class _UIntType, long unsigned int __w, long unsigned int __n, long unsigned int __m, long unsigned int __r, _UIntType __a, long unsigned int __u, _UIntType __d, long unsigned int __s, _UIntType __b, long unsigned int __t, _UIntType __c, long unsigned int __l, _UIntType __f, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>&)
/usr/include/c++/4.6/bits/random.tcc:642:5: note: template<class _UIntType, long unsigned int __w, long unsigned int __s, long unsigned int __r, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::subtract_with_carry_engine<_UIntType, __w, __s, __r>&)
/usr/include/c++/4.6/bits/random.tcc:709:5: note: template<class _RandomNumberEngine, long unsigned int __p, long unsigned int __r, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::discard_block_engine<_RandomNumberEngine, __p, __r>&)
/usr/include/c++/4.6/bits/random.tcc:815:5: note: template<class _RandomNumberEngine, long unsigned int __k, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::shuffle_order_engine<_RandomNumberEngine, __k>&)
/usr/include/c++/4.6/bits/random.tcc:1138:5: note: template<class _IntType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::negative_binomial_distribution<_IntType>&)
/usr/include/c++/4.6/bits/random.tcc:1328:5: note: template<class _IntType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::poisson_distribution<_IntType>&)
/usr/include/c++/4.6/bits/random.tcc:1577:5: note: template<class _IntType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::binomial_distribution<_IntType>&)
/usr/include/c++/4.6/bits/random.tcc:1782:5: note: template<class _RealType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::lognormal_distribution<_RealType>&)
/usr/include/c++/4.6/bits/random.tcc:1827:5: note: template<class _RealType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::chi_squared_distribution<_RealType>&)
/usr/include/c++/4.6/bits/random.tcc:1936:5: note: template<class _RealType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::fisher_f_distribution<_RealType>&)
/usr/include/c++/4.6/bits/random.tcc:1981:5: note: template<class _RealType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::student_t_distribution<_RealType>&)
/usr/include/c++/4.6/bits/random.tcc:2308:5: note: template<class _IntType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::discrete_distribution<_IntType>&)
/usr/include/c++/4.6/bits/random.tcc:2488:5: note: template<class _RealType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::piecewise_constant_distribution<_RealType>&)
/usr/include/c++/4.6/bits/random.tcc:2690:5: note: template<class _RealType, class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::piecewise_linear_distribution<_RealType>&)
/usr/include/c++/4.6/bits/istream.tcc:957:5: note: template<class _CharT2, class _Traits2> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, _CharT2*)
/usr/include/c++/4.6/bits/istream.tcc:925:5: note: template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, _CharT&)
/usr/include/c++/4.6/istream:709:5: note: template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, unsigned char&)
/usr/include/c++/4.6/istream:714:5: note: template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, signed char&)
/usr/include/c++/4.6/istream:756:5: note: template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, unsigned char*)
/usr/include/c++/4.6/istream:761:5: note: template<class _Traits> std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, _Traits>&, signed char*)
/usr/include/c++/4.6/istream:852:5: note: std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&&, _Tp&) [with _CharT = char, _Traits = std::char_traits<char>, _Tp = std::pair<float, int>] <near match>
/usr/include/c++/4.6/istream:852:5: note:   no known conversion for argument 1 from ‘std::istream_iterator<std::pair<float, int> >::istream_type {aka std::basic_istream<char>}’ to ‘std::basic_istream<char>&&’
/usr/include/c++/4.6/iomanip:70:5: note: template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::_Resetiosflags)
/usr/include/c++/4.6/iomanip:100:5: note: template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::_Setiosflags)
/usr/include/c++/4.6/iomanip:131:5: note: template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::_Setbase)
/usr/include/c++/4.6/iomanip:169:5: note: template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::_Setfill<_CharT>)
/usr/include/c++/4.6/iomanip:199:5: note: template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::_Setprecision)
/usr/include/c++/4.6/iomanip:229:5: note: template<class _CharT, class _Traits> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::_Setw)
/usr/include/c++/4.6/iomanip:263:5: note: template<class _CharT, class _Traits, class _MoneyT> std::basic_istream<_CharT, _Traits>& std::operator>>(std::basic_istream<_CharT, _Traits>&, std::_Get_money<_MoneyT>)
make: *** [filestream] Error 1

在/usr/include/c++/4.6/iterator:66:0中包含的文件中，
来自filestream.cpp:9：
/usr/include/c++/4.6/bits/stream_iterator.h:在成员函数“void std:：istream_iterator:：_M_read（）[with _Tp=std:：pair，_CharT=char，_Traits=std:：char_Traits，_Dist=long int]：
/usr/include/c++/4.6/bits/stream\u iterator.h:70:9：从“std:：istream\u iterator:：istream\u iterator:：istream\u type&”）实例化[with Tp=std:：pair，CharT=char，Traits=std:：char\u Traits，Dist=long int，std:：istream\u iterator:：istream\u type=std:：basic\u istream]
filestream.cpp:32:33:从此处实例化
/usr/include/c++/4.6/bits/stream\u iterator.h:121:6：错误：在“*（（std:：istream\u iterator*）this）->std:：istream\u iterator:：_M\u stream>>（（std:：istream\u iterator*）this）->std:：istream\u iterator:_M\u value”
/usr/include/c++/4.6/bits/stream_迭代器。h:121:6：注：候选项包括：
/usr/include/c++/4.6/istream:122:7：注：std:：basic\u istream:：：\u istream类型&std:：basic\u istream:：operator>（std:：basic\u istream:：\u istream类型&（*）（std:：basic\u istream:：\u istream类型&）[带CharT=char，\u Traits=std:：basic\u istream:：\u类型=std:：basic\u istream=std]
/usr/include/c++/4.6/istream:122:7：注意：参数1从'std:：pair'到'std:：basic_istream:：__istream_type&（*）（std:：basic_istream:：__istream_type&）{aka std:：basic_istream&（*）（std:：basic_istream&）}
/usr/include/c++/4.6/istream:126:7：注：std:：basic\u istream:：\u istream类型&std:：basic\u istream:：operator>>（std:：basic\u istream:：\u ios类型和（*）（std:：basic\u istream:：\u ios类型和）[带字符，\u traitits=char，std:：basic\u istream:：\u ios类型=std:：basic\uU ios类型，std:：basic\ios:]
/usr/include/c++/4.6/istream:126:7：注意：参数1从'std:：pair'到'std:：basic_istream:：__ios_type&（*）（std:：basic_istream:：_ios_type&）{aka std:：basic_ios&（*）（std:：basic_ios&）}
/usr/include/c++/4.6/istream:133:7：注：std:：basic\u istream:：\u istream类型和std:：basic\u istream:：operator>>（std:：ios\u base&（*）（std:：ios\u base&）[带字符，\u字符=std:：char\u字符，std:：basic\u istream:：：\uU istream\u类型=std:：basic\u istream]
/usr/include/c++/4.6/istream:133:7:注意：参数1从'std:：pair'到'std:：ios_base&（*）（std:：ios_base&'）没有已知的转换
/usr/include/c++/4.6/istream:169:7：注：std:：basic\u istream:：：\u istream\u type&std:：basic\u istream:：operator>>（bool&）[带字符，\u Traits=std:：char\u Traits，std:：basic\u istream:：\u istream\u type=std:：basic\u istream]
/usr/include/c++/4.6/istream:169:7:注意：参数1从'std:：pair'到'bool&'的转换未知
/usr/include/c++/4.6/istream:173:7：注：std:：basic_-istream&std:：basic_-istream:：operator>>（短int&）[带_-CharT=char，_-Traits=std:：char\u-Traits]
/usr/include/c++/4.6/istream:173:7:注意：参数1从'std:：pair'到'short int&'的转换未知
/usr/include/c++/4.6/istream:176:7：注：std:：basic\u istream:：\u istream\u type&std:：basic\u istream:：operator>>（短无符号int&）[带字符，\u Traits=std:：char\u Traits，std:：basic\u istream:：\u istream\u type=std:：basic\u istream]
/usr/include/c++/4.6/istream:176:7:注意：参数1从'std:：pair'到'short unsigned int&'的转换未知
/usr/include/c++/4.6/istream:180:7：注：std:：basic_-istream&std:：basic_-istream:：operator>>（int&）[带_-CharT=char，_-Traits=std:：char\u-Traits]
/usr/include/c++/4.6/istream:180:7:注意：参数1从'std:：pair'到'int&'没有已知的转换
/usr/include/c++/4.6/istream:183:7：注：std:：basic\u istream:：：\u istream\u type&std:：basic\u istream:：operator>>（unsigned int&）[带字符，\u Traits=std:：char\u Traits，std:：basic\u istream:：\u istream\u type=std:：basic\u istream]
/usr/include/c++/4.6/istream:183:7:注意：参数1从'std:：pair'到'unsigned int&'的转换未知
/usr/include/c++/4.6/istream:187:7：注：std:：basic\u istream:：：\u istream类型&std:：basic\u istream:：operator>>（long int&）[带字符，\u Traits=std:：char\u Traits，std:：basic\u istream:：\u istream\u type=std:：basic\u istream]
/usr/include/c++/4.6/istream:187:7:注意：参数1从'std:：pair'到'long int&'的转换未知
/usr/include/c++/4.6/istream:191:7：注：std:：basic\u istream:：：\u istream\u type&std:：basic\u istream:：operator>>（长无符号int&）[带"CharT=char，"Traits=std:：char\u Traits，std:：basic\u istream:：(uu istream\u type=std:：basic\u istream]
/usr/include/c++/4.6/istream:191:7:注意：参数1从'std:：pair'到'long unsigned int&'的转换未知
/usr/include/c++/4.6/istream:196:7：注：std:：basic\u istream:：：\u istream\u type&std:：basic\u istream:：operator>>（长整型）[带字符，\u Traits=std:：char\u Traits，std:：basic\u istream:：\u istream\u type=std:：basic\u istream]
/usr/include/c++/4.6/istream:196:7:注意：参数1从'std:：pair'到'long-long-int&'的转换未知
/usr/include/c++/4.6/istream:200:7：注：std:：basic\u istream:：\u istream\u type&std:：basic\u istream:：operator>>（长-长无符号int&）[带字符，\u Traits=std:：char\u Traits，std:：basic\u istream:：\u istream\u type=std:：basic\u istream]
/usr/include/c++/4.6/istream:200:7:注意：参数1从'std:：pair'到'long unsigned int&'的转换未知
/usr/include/c++/4.6/istream:205:7：注：std:：basic\u istream:：：\uu istream类型&std:：basic\u istream:：operator>>（float&）[带CharT=char，Traits=char:：Traits，std:：basic\u istream:：\uu istream类型=std:：basic\u istream]
/usr/include/c++/4.6/istream:205:7:注意：对于来自的参数1，没有已知的转换
T t;
infile >> t;

struct T : public std::pair<int,float> {};

#include <utility>
#include <iostream>
#include <iterator>

struct T : std::pair<float, int> {
    using std::pair<float, int>::pair;
};

std::istream& operator>>(std::istream& stream, T& in) {
    return stream >> in.first >> in.second;
}

int main() {
    std::istream_iterator<T> iit(std::cin);
    std::istream_iterator<T> eos;
    while (iit != eos) {
        std::cout << (*iit).first << std::endl;
        ++iit;
    }
}

typedef pair<float, int> T;

namespace std {
    istream& operator>>(istream& stream, T& in) {
        stream >> in.first >> in.second;
        return stream;
    }
}

int main(int argc, char **argv) {
    ifstream infile("dummy2");
    istream_iterator<T> iit(infile);
    istream_iterator<T> eos;
    while (iit != eos) {
        cout << (*iit).first << endl;
        ++iit;
    }
    return 0;
}