compiling issues..please help

I am having problems getting this code to run correctly:

Code:

// wordstat.cpp
// STL version of word statistics utility
// The program parses an input text file
// and assigns the words to a std::list.
// Sort the list in alphabetical order and remove
// duplicate items. 
// Operator== is overloaded to determine duplicate-ness
// of two items. If a duplicate item is found, 
// the word counter gets increased.
//
// Feb. 25, 2001 - accepts cin from console as well as a file.
//
#include <list>
#include <string>
#include <iostream>
#include <fstream>

class node
{
public:

	node(std::string& s) : word(s), count(1) {}; // ctor

	bool operator<(node const& n) const {
		return (word < n.word);
	};

	bool operator==(node& n) {
		if(word == n.word) {
			this->count++; // duplicate found. Increase counter.
			return true;
		}
		else
			return false;
	};

	friend std::ostream& operator<<(std::ostream& os, const node& n);

private:

	std::string word;
	int count; /* word counter */

};

std::ostream& operator<<(std::ostream& os, const node& n)
{ 
	os << n.count << "\t" << n.word;
	return os; 
}

// retrieve text from an input stream
// and build words list.
bool retrieve_text(std::list<node>& words,  // words list
std::istream &is,  // stream to open
const std::string& delim) // delimiter; used to parse text
{

	std::string textline;
	while(is >> textline) {
		std::string::size_type pos = 0, pos_end;
		if((pos = textline.find_first_not_of(delim, pos)) != std::string::npos) {
			while((pos_end = textline.find_first_of(delim, pos)) != std::string::npos)
			{
				if( pos != pos_end)
					words.push_back(textline.substr(pos, pos_end - pos));
				pos = textline.find_first_not_of(delim, pos_end);
			}
			if( pos != pos_end)
				words.push_back(textline.substr(pos, pos_end - pos));
		}
	}
	return true;
}

int main(int argc, char **argv)
{
	const std::string delim = " \t\n\r.,;:()\"";
	std::list<node> words;

	if(argc >= 2) {
		std::ifstream file;
		file.open(argv[1]);
		if(file)
			retrieve_text(words, file, delim);
		else{
			std::cerr<< "File not found.\n";
			exit(-1);
		}
	}
	else{
		retrieve_text(words, std::cin, delim);
	}
		
	words.sort();
	words.unique(); // remove duplicates

	// display word statistics
	std::list<node>::iterator iter=words.begin(), iter_end = words.end();
	for(; iter != iter_end; ++iter)
		std::cout << (*iter) << std::endl;

	return 0;
}

these are the problems the debugger is giving me but i cant figure them out because i am relatively new to the c language.

line 66 no matching function for call to `std::list<node, std::allocator<node> >:: push_back(std::basic_string<char, std::char_traits<char>, std::allocator<char> >)'

line 70 no matching function for call to `std::list<node, std::allocator<node> >:: push_back(std::basic_string<char, std::char_traits<char>, std::allocator<char> >)'

Any help is greatly appreciated

Perhaps something like this:

Code:

            if ( pos != pos_end )
            {
               std::string sub(textline.substr(pos, pos_end - pos));
               words.push_back(sub);
            }

It has to do with reference/value semantics.

tried that, didnt work... thanks tho

It seems that making the constructor of node take a constant string fixes the problem.

anon could u show me how to do that, i am very new with the c language

Put the word const in front of string& s in the parameter list of the node constructor. Since you aren't modifying s, it can be const.

It needs to be const because the return value of substr is just a temporary string, and you are trying to convert that temporary string to a node. Without the const, the node class only allows modifiable strings to be used with its constructor. It makes no sense to modify a temporary object (it will be destroyed immediately anyway) so the compiler makes you guarantee that you won't be modifying it.