How to make negate_unary work with any type?

Posted by Chan on Stack Overflow See other posts from Stack Overflow or by Chan
Published on 2011-01-04T21:06:28Z Indexed on 2011/01/04 21:54 UTC
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Hi, Following this question: How to negate a predicate function using operator ! in C++?
I want to create an operator ! can work with any functor that inherited from unary_function. I tried:

template<typename T>
inline std::unary_negate<T> operator !( const T& pred ) {
 return std::not1( pred );
}

The compiler complained:

Error 5 error C2955: 'std::unary_function' : use of class template requires template argument list c:\program files\microsoft visual studio 10.0\vc\include\xfunctional 223 1 Graphic
Error 7 error C2451: conditional expression of type 'std::unary_negate<_Fn1>' is illegal c:\program files\microsoft visual studio 10.0\vc\include\ostream 529 1 Graphic
Error 3 error C2146: syntax error : missing ',' before identifier 'argument_type' c:\program files\microsoft visual studio 10.0\vc\include\xfunctional 222 1 Graphic
Error 4 error C2065: 'argument_type' : undeclared identifier c:\program files\microsoft visual studio 10.0\vc\include\xfunctional 222 1 Graphic
Error 2 error C2039: 'argument_type' : is not a member of 'std::basic_ostream<_Elem,_Traits>::sentry' c:\program files\microsoft visual studio 10.0\vc\include\xfunctional 222 1 Graphic
Error 6 error C2039: 'argument_type' : is not a member of 'std::basic_ostream<_Elem,_Traits>::sentry' c:\program files\microsoft visual studio 10.0\vc\include\xfunctional 230 1 Graphic

Any idea?

Update
Follow "templatetypedef" solution, I got new error:

Error 3 error C2831: 'operator !' cannot have default parameters c:\visual studio 2010 projects\graphic\graphic\main.cpp 39 1 Graphic
Error 2 error C2808: unary 'operator !' has too many formal parameters c:\visual studio 2010 projects\graphic\graphic\main.cpp 39 1 Graphic
Error 4 error C2675: unary '!' : 'is_prime' does not define this operator or a conversion to a type acceptable to the predefined operator c:\visual studio 2010 projects\graphic\graphic\main.cpp 52 1 Graphic

Update 1
Complete code:

#include <iostream>
#include <functional>
#include <utility>
#include <cmath>
#include <algorithm>
#include <iterator>
#include <string>

#include <boost/assign.hpp>
#include <boost/assign/std/vector.hpp>
#include <boost/assign/std/map.hpp>
#include <boost/assign/std/set.hpp>
#include <boost/assign/std/list.hpp>
#include <boost/assign/std/stack.hpp>
#include <boost/assign/std/deque.hpp>

struct is_prime : std::unary_function<int, bool> {
 bool operator()( int n ) const {
  if( n < 2 )
   return 0;
  if( n == 2 || n == 3 )
   return 1;
  if( n % 2 == 0 || n % 3 == 0 )
   return 0;
  int upper_bound = std::sqrt( static_cast<double>( n ) );
  for( int pf = 5, step = 2; pf <= upper_bound; ) {
   if( n % pf == 0 )
    return 0;
   pf  += step;
   step = 6 - step;
  }
  return 1;
 }
};

/*
template<typename T>
inline std::unary_negate<T> operator !( const T& pred, typename T::argument_type* dummy = 0 ) {
 return std::not1<T>( pred );
}
*/

inline std::unary_negate<is_prime> operator !( const is_prime& pred ) {
 return std::not1( pred );
}

template<typename T>
inline void print_con( const T& con, const std::string& ms = "", const std::string& sep = ", " ) {
 std::cout << ms << '\n';
 std::copy( con.begin(), con.end(), std::ostream_iterator<typename T::value_type>( std::cout, sep.c_str() ) );
 std::cout << "\n\n";
}

int main() {
 using namespace boost::assign;
 std::vector<int> nums;
 nums += 1, 3, 5, 7, 9;
 nums.erase( remove_if( nums.begin(), nums.end(), !is_prime() ), nums.end() );
 print_con( nums, "After remove all primes" ); 
}

Thanks,
Chan Nguyen

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