#pragma hdrstop
#pragma argsused
 
#ifdef _WIN32
#include <tchar.h>
#else
  typedef char _TCHAR;
  #define _tmain main
#endif
 
#include <stdio.h>
#include <complex>
#include <vector>
#include <algorithm>
 
typedef std::complex<double> Complex;
 
bool operator<(const Complex & lhs, const Complex & rhs)
{
	return lhs.real() < rhs.real();
}
 
void doSort()
{
	std::vector<Complex> vc;
	std::sort(vc.begin(), vc.end());
}
 
int _tmain(int argc, _TCHAR* argv[])
{
	doSort();
	return 0;
}

[bcc32c Error] algorithm(3077): no matching function for call to object of type 'std::less<void>'
  algorithm(3094): in instantiation of function template specialization 'std::_Med3<std::complex<double> *, std::less<void> >' requested here
  algorithm(3109): in instantiation of function template specialization 'std::_Median<std::complex<double> *, std::less<void> >' requested here
  algorithm(3171): in instantiation of function template specialization 'std::_Unguarded_partition<std::complex<double> *, std::less<void> >' requested here
  algorithm(3201): in instantiation of function template specialization 'std::_Sort<std::complex<double> *, int, std::less<void> >' requested here
  algorithm(3208): in instantiation of function template specialization 'std::sort<std::_Vector_iterator<std::_Vector_val<std::_Simple_types<std::complex<double> > > >, std::less<void> >' requested here
  File4.cpp(26): in instantiation of function template specialization 'std::sort<std::_Vector_iterator<std::_Vector_val<std::_Simple_types<std::complex<double> > > > >' requested here
  xstddef(339): candidate template ignored: substitution failure [with _Ty1 = std::complex<double> &, _Ty2 = std::complex<double> &]: invalid operands to binary expression ('std::complex<double>' and 'std::complex<double>')