Problem Compiling Program

Hi, I'm writing a program that reads in a string and removes the vowels from that string. For that, I wrote a function, known as compress(string& w), which removes the vowels. I'll show the header file, the main function, and the compress function. After that I will display the error message that it is generating. Thanks for any possible help.

The Header File "compress.h"

Code:

void compress(string& w);

The Main Program

Code:

#include <iostream> #include <stdlib.h> #include <vector> #include <algorithm> using namespace std; #include "compress.h" int main() { string word; vector<string> words; //Reads and removes vowels while (cin >> word) { compress(word); words.push_back(word); } //Sorts the words in alphabetical order sort(words.begin(), words.end()); for (int i=0; i<words.size(); i++) { cout << words[i] << endl; } return (0); }

Finally, the Function

Code:

#include <string> using namespace std; #include "compress.h" const char VOWELS[] = "aeiou"; const int VMAX = 5; void compress(string& w) { string temp = w; //... Iterate character-by-character over each string. for (int i=w.size()-1; i >= 0; i--) { //... Iterate over each of the vowel characters. for (int v=0; v<VMAX; v++) { if (w[i] == VOWELS[v]) { // When it's a vowel w.erase(i, 1); // Remove it. break; // Try next word character. } } } }

This is the error message I am getting...

Code:

1>------ Rebuild All started: Project: Number 1B, Configuration: Debug Win32 ------ 1>Deleting intermediate and output files for project 'Number 1B', configuration 'Debug|Win32' 1>Compiling... 1>Number 1B.cpp 1>e:\visual studio 2005\projects\homework 8\number 1b\number 1b\number 1b.cpp(23) : error C2679: binary '>>' : no operator found which takes a right-hand operand of type 'std::string' (or there is no acceptable conversion) 1> c:\program files\microsoft visual studio 8\vc\include\istream(1137): could be 'std::basic_istream<_Elem,_Traits> &std::operator >><std::char_traits<char>>(std::basic_istream<_Elem,_Traits> &,signed char *)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> c:\program files\microsoft visual studio 8\vc\include\istream(1139): or 'std::basic_istream<_Elem,_Traits> &std::operator >><std::char_traits<char>>(std::basic_istream<_Elem,_Traits> &,signed char &)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> c:\program files\microsoft visual studio 8\vc\include\istream(1141): or 'std::basic_istream<_Elem,_Traits> &std::operator >><std::char_traits<char>>(std::basic_istream<_Elem,_Traits> &,unsigned char *)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> c:\program files\microsoft visual studio 8\vc\include\istream(1143): or 'std::basic_istream<_Elem,_Traits> &std::operator >><std::char_traits<char>>(std::basic_istream<_Elem,_Traits> &,unsigned char &)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> c:\program files\microsoft visual studio 8\vc\include\istream(155): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(std::basic_istream<_Elem,_Traits> &(__cdecl *)(std::basic_istream<_Elem,_Traits> &))' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> c:\program files\microsoft visual studio 8\vc\include\istream(161): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(std::basic_ios<_Elem,_Traits> &(__cdecl *)(std::basic_ios<_Elem,_Traits> &))' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> c:\program files\microsoft visual studio 8\vc\include\istream(168): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(std::ios_base &(__cdecl *)(std::ios_base &))' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> c:\program files\microsoft visual studio 8\vc\include\istream(175): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(std::_Bool &)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> c:\program files\microsoft visual studio 8\vc\include\istream(194): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(short &)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> c:\program files\microsoft visual studio 8\vc\include\istream(228): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(unsigned short &)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> c:\program files\microsoft visual studio 8\vc\include\istream(247): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(int &)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> c:\program files\microsoft visual studio 8\vc\include\istream(273): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(unsigned int &)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> c:\program files\microsoft visual studio 8\vc\include\istream(291): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(long &)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> c:\program files\microsoft visual studio 8\vc\include\istream(309): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(__w64 unsigned long &)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> c:\program files\microsoft visual studio 8\vc\include\istream(329): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(__int64 &)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> c:\program files\microsoft visual studio 8\vc\include\istream(348): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(unsigned __int64 &)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> c:\program files\microsoft visual studio 8\vc\include\istream(367): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(float &)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> c:\program files\microsoft visual studio 8\vc\include\istream(386): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(double &)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> c:\program files\microsoft visual studio 8\vc\include\istream(404): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(long double &)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> c:\program files\microsoft visual studio 8\vc\include\istream(422): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(void *&)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> c:\program files\microsoft visual studio 8\vc\include\istream(441): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(std::basic_streambuf<_Elem,_Traits> *)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> while trying to match the argument list '(std::istream, std::string)' 1>e:\visual studio 2005\projects\homework 8\number 1b\number 1b\number 1b.cpp(23) : fatal error C1903: unable to recover from previous error(s); stopping compilation 1>compress.cpp 1>e:\visual studio 2005\projects\homework 8\number 1b\number 1b\compress.cpp(26) : warning C4267: 'initializing' : conversion from 'size_t' to 'int', possible loss of data 1>Generating Code... 1>Build log was saved at "file://e:\Visual Studio 2005\Projects\Homework 8\Number 1B\Number 1B\Debug\BuildLog.htm" 1>Number 1B - 2 error(s), 1 warning(s) ========== Rebuild All: 0 succeeded, 1 failed, 0 skipped ==========

Sorry for all of this, but I wanted to be thorough...
Any help is greatly appreciated!

do you #include <string> ?

and can your compress function handle strings with multiple vowels in a row? ("feel" ? When you erase that first e, everything will shift one)

Also: Indentation will make your code a thousand times more readable. Invest in some whitespace. ;)

Thanks is was that I just forgot to #include <string>

Also, to get my program to stop accepting inputs I have to include a sentinel value. I've worked with these before, but I'm still not 100% sure of how to implement, any help?

Simple:

Code:

while (cin >> word && word != sentinel)

Thanks, got the program running correctly now!

Argh, don't use "using namespace std;"

If you DO choose to do this, include all header files BEFORE it!

"using namespace" completely changes the meaning of all code following it, including code from header files.

I'm in an entry level C++ programming class at Penn State University, my professor has always instructed us to use 'using namespace std;' although he has never explained it's purpose or use. However, the program ran correctly, so what affect would including the header file before or after the 'namespace' have?

Thanks for the insight.

Quote:

However, the program ran correctly, so what affect would including the header file before or after the 'namespace' have?

All the names from the std namespace in those standard headers included would have been introduced into the current file's scope. This increases the chance of a naming conflict. You may be able to spot and work around the name conflict in the current file, but since this is propagated to other header files that were included after the using directive, you may end up with a big mess.

If he simply moves "using namespace std" after the includes, the program won't compile, because his prototypes use standard containers.

I recommend keeping the practice of putting "using namespace std" before headers, until you learn about namespaces and what the using directive does. Alternatively, you can learn all that now, so that you're not practicing a bad practice.

Quote:

Originally Posted by King Mir

I recommend keeping the practice of putting "using namespace std" before headers, until you learn about namespaces and what the using directive does. Alternatively, you can learn all that now, so that you're not practicing a bad practice.

So his header file is broken. It doesn't work unless the user knows to put "using namespace std;" before including it? Very poor, IMO.

If compress.h needs the using directive, it should have the using directive inside it. It should not rely on source files that include it to have a using directive before its inclusion. It should also #include <string> for the same reason.

It's not good practice to have a using directive in a header file, though, so a simple solution would be to #include <string> and refer to it as std::string inside compress.h.

For a small program like this, I don't think it's a big deal, though, especially if that's what the instructor prefers. Just know that it's generally considered bad practice to have a using directive in a header or in a source file before header includes.

Quote:

Originally Posted by Daved

If compress.h needs the using directive, it should have the using directive inside it. It should not rely on source files that include it to have a using directive before its inclusion. It should also #include <string> for the same reason.

I could argue about this, but you're right. It's a small piece of code, written for an instructor who may not have ALL his marbles. To the original poster -- keep it in mind. "using namespace" is not something you typically should be using.

Quote:

Originally Posted by wco5002

I'm in an entry level C++ programming class at Penn State University

Damn PSU'ers! You guys are the reason my alma mater of Portland State University has to go by the acronym "PDX" instead of "PSU!" To hell with you people!

I kid! :)

Quote:

For a small program like this, I don't think it's a big deal, though, especially if that's what the instructor prefers.

To be fair, we do not really know what the professor prefers. Perhaps he did not expect his students to place the using directive before including a header, but he did not include negative examples concerning this so some students, like wco5002, did so.