Can't understand my error...

So I am trying to write this small program using a void method from a source file but it does not work..It is giving me some weird error, that I can't comprehend. My code SEEMS correct but maybe you real programmers out there can help me point out my mistake, as the error is

Code:

main.obj : error LNK2019: unresolved external symbol "void __cdecl ordered(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,class std::list<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,class std::allocator<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > > >)" (?ordered@@YAXV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@V?$list@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@V?$allocator@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@2@@2@@Z) referenced in function _main

Here are my 3 files

Code:

#include <iostream>
#include <list>
#include <string>
#include "oLine.h"
#include <vector>

using std::cout;
using std::endl;
using std::string;
using std::cin;
using std::list;

int main(){

	//asks for user input
	cout << "Please type in your input: ";
	
	//the container
	list<string> sentence;
	string x;
	
	//adds user input to container
	while(cin >> x){
		sentence.push_back(x);
		}
	
	//sorts out sentence
	list<string> sorted = sentence;
	sorted.sort();
	
	//starts container from beginning, and continues until the end
	for(list<string>::iterator iter = sorted.begin(); iter != sorted.end(); iter++){
		ordered(*iter, sentence);
	}


	return 0;

}

Code:

#ifndef GUARD_oLine_h
#define GUARD_oline_h

//oline.h

#include <string>
#include <list>

void ordered(std::string, std::list<std::string>);

#endif

Code:

#include "oLine.h"
#include <string>
#include <iostream>
#include <list>

using std::string;
using std::cout;
using std::list;

void ordered(string& start, list<string>& phrase){
	
	//counts the number of words outputted
	list<string>::iterator count = phrase.begin();
	//current word the iterator is on
	list<string>::iterator current = phrase.begin();
	
	//while the count is not the end
	while(count != phrase.end()){
		
		//if start equals current and current isnt the end
		//we output current and increment current along with the count
		if(start == *current && current != phrase.end()){
			cout << *current << ' ';
			current++;
			count++;
		}
		
		//since it is the end, we output current and set it back to the beginning
		else if(start == *current && current == phrase.end()){
			cout << *current << ' ';
			current = phrase.begin();
			count++;
		}
		
		//otherwise just increment current
		else{
			current++;
		}

	}

}

Thanks for your help!

you're declaring it as

Code:

void ordered(std::string, std::list<std::string>);

but defining it as

Code:

void ordered(string& start, list<string>& phrase)

can't have references in one spot and not in the other. also, even with the using statements, you should declare the types the same way in both. either std::x or just x. just do it the same everywhere for the sake of clarity.

Thank you for your reply! So should I have it like this? I actually just tried that and its pretty much giving me the same error.

Code:

void ordered(std::string&, std::list<std::string>&);


void ordered(string& start, list<string>& phrase)

do you compile 2 files together?

You have added all project files to your project?
Also, don't remove the names of parameters in the prototypes.

Originally Posted by dnguyen1022

Thank you for your reply! So should I have it like this? I actually just tried that and its pretty much giving me the same error.

Code:

void ordered(std::string&, std::list<std::string>&);


void ordered(string& start, list<string>& phrase)

actually it should be more like

Code:

void ordered(std::string& start, std::list<std::string>& phrase);

void ordered(std::string& start, std::list<std::string>& phrase)
{
  // code
}

your declaration should always exactly match your definition.

Originally Posted by Elysia

You have added all project files to your project?
Also, don't remove the names of parameters in the prototypes.

Eh..what do you mean by the names of parameters in the prototypes? I am self-teaching myself c++, so the terms are unfamiliar to me.

A prototype is a function declaration, telling the compiler "somewhere, but not here, there is a function X, returning something of type T, and takes parameters ...". It is NECESSARY in a prototype to declare the types of parameters, and what Elysia says is that you should put the names of the parameters too (which isn't strictly required).

--
Mats

Originally Posted by dnguyen1022

Eh..what do you mean by the names of parameters in the prototypes? I am self-teaching myself c++, so the terms are unfamiliar to me.

That's why I gave you a link. I think it pretty clearly explains the problem and why it's a bad thing.

Originally Posted by Elysia

That's why I gave you a link. I think it pretty clearly explains the problem and why it's a bad thing.

Sorry about that, I had no idea it was a link lol. I thought you just simply highlighted it in red. I understand now. Thank you!

However my code is still giving me the same error. I am definitely trying to compile these files together. I even tried to change the name of my header file to see if it was actually attempting to read it. As expected it couldn't find the file. Just in case..here is my coding once again..

[code]
#include <iostream>
#include <list>
#include <string>
#include "oLine.h"
#include <vector>

using std::cout;
using std::endl;
using std::string;
using std::cin;
using std::list;

int main(){

//asks for user input
cout << "Please type in your input: ";

//the container
list<string> sentence;
string x;

//adds user input to container
while(cin >> x){
sentence.push_back(x);
}

//sorts out sentence
list<string> sorted = sentence;
sorted.sort();

//starts container from beginning, and continues until the end
for(list<string>::iterator iter = sorted.begin(); iter != sorted.end(); iter++){
ordered(*iter, sentence);
}


return 0;

}
[code]

Code:

#ifndef GUARD_oLine_h
#define GUARD_oline_h

//oline.h

#include <string>
#include <list>

void ordered(std::string&, std::list<std::string>&);

#endif

Code:

#include "oLine.h"
#include <string>
#include <iostream>
#include <list>

using std::string;
using std::cout;
using std::list;

void ordered(std::string& start, std::list<std::string>& phrase){
	
	//counts the number of words outputted
	list<string>::iterator count = phrase.begin();
	//current word the iterator is on
	list<string>::iterator current = phrase.begin();
	
	//while the count is not the end
	while(count != phrase.end()){
		
		//if start equals current and current isnt the end
		//we output current and increment current along with the count
		if(start == *current && current != phrase.end()){
			cout << *current << ' ';
			current++;
			count++;
		}
		
		//since it is the end, we output current and set it back to the beginning
		else if(start == *current && current == phrase.end()){
			cout << *current << ' ';
			current = phrase.begin();
			count++;
		}
		
		//otherwise just increment current
		else{
			current++;
		}

	}

}

Anybody with VS 2008 that could kindly try compiling these files to see what happens? Maybe I may actually be doing something wrong here, which I think is highly possible.

Compiles and links fine (single source file).
It's more probably that you did not add your source files to the project. You never answered if you did.

OK, so I figured out that my problem was not putting it in the correct folders within the solution. I had everything in the same folder, when I should have put the header file in its own folder.

As for the code, it clearly is not working. It will simply output the first word that is suppose to come out first according to the sort function. It crashes right on the second word. Using the little skills I have with the debugger. It seems like it is having problems when I am incrementing current++ within my source file code.

This is the code..

Code:

#include "oLine.h"
#include <string>
#include <iostream>
#include <list>

using std::string;
using std::cout;
using std::list;

void ordered(std::string& start, std::list<std::string>& phrase){
	
	//counts the number of words outputted
	list<string>::iterator count = phrase.begin();
	//current word the iterator is on
	list<string>::iterator current = phrase.begin();
	
	//while the count is not the end
	while(count != phrase.end()){
		
		//if start equals current and current isnt the end
		//we output current and increment current along with the count
		if((start == *current) && (current != phrase.end())){
			cout << *current << ' ';
			current++;
			count++;
		}
		
		//since it is the end, we output current and set it back to the beginning
		else if((start == *current) && (current == phrase.end())){
			cout << *current << ' ';
			current = phrase.begin();
			count++;
		}
		
		//otherwise just increment current
		else{
			current++;
		}

	}

}

I think it may be over incrementing, since phrase.end() is actually the one past the last word. I am unsure of how to fix this though. I feel that my if statements are not correctly covering all my cases, and I think that is where I should fix the problem so that it will not over increment. Help greatly appreciated!

What is the ordered function supposed to do?

Basically take in a string, and a phrase. Find that string in the phrase, and then output that phrase starting from that string. If that string is in the middle of the phrase, output until it hits the end, and recurse back to the beginning of the phrase and output until count hits phrase.end(), or if count was an int, phrase's size. It should keep recursing as long as count does not equal to phrase.end(). This is kind of vague, so here is an example

string: blue
phrase: two blue dogs

output: blue dogs two

This is a helper function, and my main code ensures that the string will be in the phrase.

So my code is no longer giving me errors but it is not outputting the right stuff. Given the input "1 2 3 4"
It gives me back
1 2 3 4
2 1 3 4
3 1 2 4
4 1 2 3

However it should be
1 2 3 4
2 3 4 1
3 4 1 2
4 1 2 3

I can't seem to find where the problem in my code is. I don't see why it is always starting back at 1 after it outputs the first correct output except.
I created another helper function rLine and I believe that is where the problem lies.

Code:

#include <iostream>
#include <list>
#include <string>
#include "oLine.h"
#include <vector>

using std::cout;
using std::endl;
using std::string;
using std::cin;
using std::list;

int main(){

	//asks for user input
	cout << "Please type in your input: ";
	
	//the container
	list<string> sentence;
	string x;
	
	//adds user input to container
	while(cin >> x){
		sentence.push_back(x);
		}
	
	//sorts out sentence
	list<string> sorted = sentence;
	sorted.sort();
	
	//starts container from beginning, and continues until the end
	for(list<string>::iterator iter = sorted.begin(); iter != sorted.end(); iter++){
		ordered(*iter, sentence);
		cout << endl;
	}


	return 0;

}

Code:

#include "oLine.h"
#include <string>
#include <iostream>
#include <list>
#include "rLine.h"

using std::string;
using std::cout;
using std::list;

void ordered(std::string& start, std::list<std::string>& phrase){
	
	//counts the number of words outputted
	list<string>::iterator count = phrase.begin();
	//current word the iterator is on
	list<string>::iterator current = phrase.begin();
	
	//while the count is not the end
	while(count != phrase.end()){

		if (current == phrase.end()){
			current = phrase.begin();
		}

		//if start equals current
		//we output current and increment current along with the count
		//and run the method "rest" for the rest of the line
		if(start == *current){
			cout << *current << ' ';
			current++;
			rest(start, phrase);
			count = phrase.end();
		}
		
		//otherwise just increment current
		else{
			current++;
		}
	}
}

Code:

#include "rLine.h"
#include <string>
#include <iostream>
#include <list>

using std::string;
using std::cout;
using std::list;

void rest(std::string& start, std::list<std::string>& phrase){
	
	//counts the number of words outputted
	list<string>::iterator count = phrase.begin();
	//current word the iterator is on
	list<string>::iterator current = phrase.begin();
	
	//while the count is not the end
	while(count != phrase.end()){
		
		//if it reaches the end set it to the beginning
		if (current == phrase.end()){
			current = phrase.begin();
		}

		//if start equals current continue along and increment current and count
		if(start == *current){
			current++;
			count++;
		}
		
		//otherwise output the current and increment current and count 
		else{
			cout << *current << ' ';
			current++;
			count++;
			}
		}

}