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Soulstorm · Jan 22nd, 2006, 10:08 AM

First of all, I want to declare that I am relatively new to programming.
Now on to the question:

I am stydying C++ for my exams. So, I am trying to do an exercise concerning templates . You don't need to know the question, since my question is not related to how can I do the exercise but rather a strange thing I want to verify:

My code is this:

(Toggle Plain Text)

#include <iostream>
#include <string>
using namespace std;


template<class T>
void set(T p[], int num, char *name){
	int i;
	for(i=0; i<num; i++){
		cout << name << "[" << i << "]=";
		cin >> p[i];
	}
}

template<class T>
void show(T p[], int num, char *name){
	int i;
	for(i=0; i<num; i++){
		cout << name << "[" << i << "]=" << p[i] << "\n";
	}
}

template<class T>
int greater(T a, T b){return(a>b);}
int greater(char *a, char *b){return strcmp(a,b)>0;}

template<class T>
void swap(T &a, T &b){
	T temp = a;
	a = b;
	b = temp;
}
void swap(char *a, char *b){
	char temp[20];
	strcpy(temp, a);
	strcpy(a,b);
	strcpy(b,temp);
}

template <class T>

void sort(T p[], int size){
	int i,k;
	for(k=1;k<size;k++)
		for(i=0;i<size-k;i++)
			if (greater(p[i],p[i+1])>0){
				swap(p[i],p[i+1]);
			}
}


int main(){
	char names[4][21]; int n=4;
	set(names,n,"names");
	cout<<"\nunsorted names a\n";
	show(names,n,"names");
	sort(names,n); 
	cout<<"\nsorted names\n"; 
	show(names,n,"names");
	int  numbers[4];
	set(numbers,3,"numbers"); 
	cout<<"\nunsorted numbers b\n";
	show(numbers,3,"numbers");
	sort(numbers,3);
	cout<<"\nsorted numbers\n"; 
	show(numbers,3,"numbers");
	
}

And it shows many errors in xCode. The errors have something to do with ambiguous declarations.

I change my code to this:

(Toggle Plain Text)

#include <iostream.h>
#include <string.h>


template<class T>
void set(T p[], int num, char *name){
	int i;
	for(i=0; i<num; i++){
		cout << name << "[" << i << "]=";
		cin >> p[i];
	}
}

template<class T>
void show(T p[], int num, char *name){
	int i;
	for(i=0; i<num; i++){
		cout << name << "[" << i << "]=" << p[i] << "\n";
	}
}

template<class T>
int greater(T a, T b){return(a>b);}
int greater(char *a, char *b){return strcmp(a,b)>0;}

template<class T>
void swap(T &a, T &b){
	T temp = a;
	a = b;
	b = temp;
}
void swap(char *a, char *b){
	char temp[20];
	strcpy(temp, a);
	strcpy(a,b);
	strcpy(b,temp);
}

template <class T>

void sort(T p[], int size){
	int i,k;
	for(k=1;k<size;k++)
		for(i=0;i<size-k;i++)
			if (greater(p[i],p[i+1])>0){
				swap(p[i],p[i+1]);
			}
}


int main(){
	char names[4][21]; int n=4;
	set(names,n,"names");
	cout<<"\nunsorted names a\n";
	show(names,n,"names");
	sort(names,n); 
	cout<<"\nsorted names\n"; 
	show(names,n,"names");
	int  numbers[4];
	set(numbers,3,"numbers"); 
	cout<<"\nunsorted numbers b\n";
	show(numbers,3,"numbers");
	sort(numbers,3);
	cout<<"\nsorted numbers\n"; 
	show(numbers,3,"numbers");
	
}

and it compiles fine. (Note that I have changed the headers and removed the namespace). Lastly, with a little thought, I ended up using this code:

(Toggle Plain Text)

#include <iostream>
#include <string>

using std::cout;
using std::cin;

template<class T>
void set(T p[], int num, char *name){
	int i;
	for(i=0; i<num; i++){
		cout << name << "[" << i << "]=";
		cin >> p[i];
	}
}

template<class T>
void show(T p[], int num, char *name){
	int i;
	for(i=0; i<num; i++){
		cout << name << "[" << i << "]=" << p[i] << "\n";
	}
}

template<class T>
int greater(T a, T b){return(a>b);}
int greater(char *a, char *b){return strcmp(a,b)>0;}

template<class T>
void swap(T &a, T &b){
	T temp = a;
	a = b;
	b = temp;
}
void swap(char *a, char *b){
	char temp[20];
	strcpy(temp, a);
	strcpy(a,b);
	strcpy(b,temp);
}

template <class T>

void sort(T p[], int size){
	int i,k;
	for(k=1;k<size;k++)
		for(i=0;i<size-k;i++)
			if (greater(p[i],p[i+1])>0){
				swap(p[i],p[i+1]);
			}
}


int main(){
	char names[4][21]; int n=4;
	set(names,n,"names");
	cout<<"\nunsorted names a\n";
	show(names,n,"names");
	sort(names,n); 
	cout<<"\nsorted names\n"; 
	show(names,n,"names");
	int  numbers[4];
	set(numbers,3,"numbers"); 
	cout<<"\nunsorted numbers b\n";
	show(numbers,3,"numbers");
	sort(numbers,3);
	cout<<"\nsorted numbers\n"; 
	show(numbers,3,"numbers");
	
}

(note that I included the specific statements to be used from the std namespace).

So i figured out it is a namespace problem. What are the commands that conflict with each other exactly?

Finally, do you know of any good reference to the commands each available namespace includes? I figured out that if I want to do some serious programming, I should get involved with namespaces and templates a lot, even if my exams don't require that.

Cache · Jan 22nd, 2006, 1:43 PM

From 'stl_functions.h' which is uses the 'std' namespace:

(Toggle Plain Text)

/// One of the @link s20_3_3_comparisons comparison functors@endlink.
  template <class _Tp>
	struct greater : public binary_function<_Tp, _Tp, bool>
	{
	  bool
	  operator()(const _Tp& __x, const _Tp& __y) const
	  { return __x > __y; }
	};

That's conflicting with your 'greater' template function.

You can either scrap the 'using namespace std' - and go for std::string (or whatever), or make your own namespace:

(Toggle Plain Text)

namespace MySpace
{
   template<class T>
   int greater(T a, T b){return(a>b);}
   int greater(char *a, char *b){return strcmp(a,b)>0;}
}

template <class T>
void sort(T p[], int size){
   
	int i,k;
	for(k=1;k<size;k++)
		for(i=0;i<size-k;i++)
			if (MySpace::greater(p[i],p[i+1])>0){
				swap(p[i],p[i+1]);
			}
}

That still leaves: "call of overloaded `swap(int&, int&)' is ambiguous", though. I haven't messed with templates enough (yet) to suggest anything for that.

EDIT: It seems to work when the whole thing is namespaced up:

(Toggle Plain Text)

#include <iostream>
#include <string>
using namespace std;

namespace MySpace
{

template<class T>
void set(T p[], int num, char *name){
	int i;
	for(i=0; i<num; i++){
		cout << name << "[" << i << "]=";
		cin >> p[i];
	}
}

template<class T>
void show(T p[], int num, char *name){
	int i;
	for(i=0; i<num; i++){
		cout << name << "[" << i << "]=" << p[i] << "\n";
	}
}


   template<class T>
   int greater(T a, T b){return(a>b);}
   int greater(char *a, char *b){return strcmp(a,b)>0;}


template<class T>
void swap(T &a, T &b){
	T temp = a;
	a = b;
	b = temp;
}
void swap(char *a, char *b){
	char temp[20];
	strcpy(temp, a);
	strcpy(a,b);
	strcpy(b,temp);
}

template <class T>
void sort(T p[], int size){
   
	int i,k;
	for(k=1;k<size;k++)
		for(i=0;i<size-k;i++)
			if (greater(p[i],p[i+1])>0){
				swap(p[i],p[i+1]);
			}
}
}


int main(){
	char names[4][21]; int n=4;
	MySpace::set(names,n,"names");
	cout<<"\nunsorted names a\n";
	MySpace::show(names,n,"names");
	MySpace::sort(names,n); 
	cout<<"\nsorted names\n"; 
	MySpace::show(names,n,"names");
	int  numbers[4];
	MySpace::set(numbers,3,"numbers"); 
	cout<<"\nunsorted numbers b\n";
	MySpace::show(numbers,3,"numbers");
	MySpace::sort(numbers,3);
	cout<<"\nsorted numbers\n"; 
	MySpace::show(numbers,3,"numbers");
	
}

Soulstorm · Jan 22nd, 2006, 2:36 PM

Thanks a lot!

So, I figured right. Because it was an examination exercise, I decided to keep the code as unchanged as I could, so I have written this code:

(Toggle Plain Text)

#include <iostream>
#include <string>

using std::cout;
using std::cin;

template<class T>
void set(T p[], int num, char *name){
	int i;
	for(i=0; i<num; i++){
		cout << name << "[" << i << "]=";
		cin >> p[i];
	}
}

template<class T>
void show(T p[], int num, char *name){
	int i;
	for(i=0; i<num; i++){
		cout << name << "[" << i << "]=" << p[i] << "\n";
	}
}

template<class T>
int greater(T a, T b){return(a>b);}
int greater(char *a, char *b){return strcmp(a,b)>0;}

template<class T>
void swap(T &a, T &b){
	T temp = a;
	a = b;
	b = temp;
}
void swap(char *a, char *b){
	char temp[20];
	strcpy(temp, a);
	strcpy(a,b);
	strcpy(b,temp);
}

template <class T>

void sort(T p[], int size){
	int i,k;
	for(k=1;k<size;k++)
		for(i=0;i<size-k;i++)
			if (greater(p[i],p[i+1])>0){
				swap(p[i],p[i+1]);
			}
}


int main(){
	char names[4][21]; int n=4;
	set(names,n,"names");
	cout<<"\nunsorted names a\n";
	show(names,n,"names");
	sort(names,n); 
	cout<<"\nsorted names\n"; 
	show(names,n,"names");
	int  numbers[4];
	set(numbers,3,"numbers"); 
	cout<<"\nunsorted numbers b\n";
	show(numbers,3,"numbers");
	sort(numbers,3);
	cout<<"\nsorted numbers\n"; 
	show(numbers,3,"numbers");
	
}

Anyway, last question still unanswered, have you got any online references to namespaces? How am I supposed to know which commands confront others in certain namespaces?

Cache · Jan 22nd, 2006, 2:46 PM

Quote:

Originally Posted by Soulstorm

So, I figured right.
Anyway, last question still unanswered, have you got any online references to namespaces? How am I supposed to know which commands confront others in certain namespaces?

Yup, and I just noticed you never even had the problem I generated lol.

For your last question: anything in the STL (Standard Template Library) in under the std namespace.

http://www.cppreference.com/cppstl.html

Jan 22nd, 2006, 10:08 AM	#1
Soulstorm Hobbyist Programmer Join Date: Jan 2006 Location: Menidi, Athens, Greece Posts: 234 Rep Power: 3	C++ template and namespace question First of all, I want to declare that I am relatively new to programming. Now on to the question: I am stydying C++ for my exams. So, I am trying to do an exercise concerning templates . You don't need to know the question, since my question is not related to how can I do the exercise but rather a strange thing I want to verify: My code is this: (Toggle Plain Text) #include <iostream> #include <string> using namespace std; template<class T> void set(T p[], int num, char name){ int i; for(i=0; i<num; i++){ cout << name << "[" << i << "]="; cin >> p[i]; } } template<class T> void show(T p[], int num, char name){ int i; for(i=0; i<num; i++){ cout << name << "[" << i << "]=" << p[i] << "\n"; } } template<class T> int greater(T a, T b){return(a>b);} int greater(char a, char b){return strcmp(a,b)>0;} template<class T> void swap(T &a, T &b){ T temp = a; a = b; b = temp; } void swap(char a, char b){ char temp[20]; strcpy(temp, a); strcpy(a,b); strcpy(b,temp); } template <class T> void sort(T p[], int size){ int i,k; for(k=1;k<size;k++) for(i=0;i<size-k;i++) if (greater(p[i],p[i+1])>0){ swap(p[i],p[i+1]); } } int main(){ char names[4][21]; int n=4; set(names,n,"names"); cout<<"\nunsorted names a\n"; show(names,n,"names"); sort(names,n); cout<<"\nsorted names\n"; show(names,n,"names"); int numbers[4]; set(numbers,3,"numbers"); cout<<"\nunsorted numbers b\n"; show(numbers,3,"numbers"); sort(numbers,3); cout<<"\nsorted numbers\n"; show(numbers,3,"numbers"); } #include <iostream> #include <string> using namespace std; template<class T> void set(T p[], int num, char name){ int i; for(i=0; i<num; i++){ cout << name << "[" << i << "]="; cin >> p[i]; } } template<class T> void show(T p[], int num, char name){ int i; for(i=0; i<num; i++){ cout << name << "[" << i << "]=" << p[i] << "\n"; } } template<class T> int greater(T a, T b){return(a>b);} int greater(char a, char b){return strcmp(a,b)>0;} template<class T> void swap(T &a, T &b){ T temp = a; a = b; b = temp; } void swap(char a, char b){ char temp[20]; strcpy(temp, a); strcpy(a,b); strcpy(b,temp); } template <class T> void sort(T p[], int size){ int i,k; for(k=1;k<size;k++) for(i=0;i<size-k;i++) if (greater(p[i],p[i+1])>0){ swap(p[i],p[i+1]); } } int main(){ char names[4][21]; int n=4; set(names,n,"names"); cout<<"\nunsorted names a\n"; show(names,n,"names"); sort(names,n); cout<<"\nsorted names\n"; show(names,n,"names"); int numbers[4]; set(numbers,3,"numbers"); cout<<"\nunsorted numbers b\n"; show(numbers,3,"numbers"); sort(numbers,3); cout<<"\nsorted numbers\n"; show(numbers,3,"numbers"); } And it shows many errors in xCode. The errors have something to do with ambiguous declarations. I change my code to this: (Toggle Plain Text) #include <iostream.h> #include <string.h> template<class T> void set(T p[], int num, char name){ int i; for(i=0; i<num; i++){ cout << name << "[" << i << "]="; cin >> p[i]; } } template<class T> void show(T p[], int num, char name){ int i; for(i=0; i<num; i++){ cout << name << "[" << i << "]=" << p[i] << "\n"; } } template<class T> int greater(T a, T b){return(a>b);} int greater(char a, char b){return strcmp(a,b)>0;} template<class T> void swap(T &a, T &b){ T temp = a; a = b; b = temp; } void swap(char a, char b){ char temp[20]; strcpy(temp, a); strcpy(a,b); strcpy(b,temp); } template <class T> void sort(T p[], int size){ int i,k; for(k=1;k<size;k++) for(i=0;i<size-k;i++) if (greater(p[i],p[i+1])>0){ swap(p[i],p[i+1]); } } int main(){ char names[4][21]; int n=4; set(names,n,"names"); cout<<"\nunsorted names a\n"; show(names,n,"names"); sort(names,n); cout<<"\nsorted names\n"; show(names,n,"names"); int numbers[4]; set(numbers,3,"numbers"); cout<<"\nunsorted numbers b\n"; show(numbers,3,"numbers"); sort(numbers,3); cout<<"\nsorted numbers\n"; show(numbers,3,"numbers"); } #include <iostream.h> #include <string.h> template<class T> void set(T p[], int num, char name){ int i; for(i=0; i<num; i++){ cout << name << "[" << i << "]="; cin >> p[i]; } } template<class T> void show(T p[], int num, char name){ int i; for(i=0; i<num; i++){ cout << name << "[" << i << "]=" << p[i] << "\n"; } } template<class T> int greater(T a, T b){return(a>b);} int greater(char a, char b){return strcmp(a,b)>0;} template<class T> void swap(T &a, T &b){ T temp = a; a = b; b = temp; } void swap(char a, char b){ char temp[20]; strcpy(temp, a); strcpy(a,b); strcpy(b,temp); } template <class T> void sort(T p[], int size){ int i,k; for(k=1;k<size;k++) for(i=0;i<size-k;i++) if (greater(p[i],p[i+1])>0){ swap(p[i],p[i+1]); } } int main(){ char names[4][21]; int n=4; set(names,n,"names"); cout<<"\nunsorted names a\n"; show(names,n,"names"); sort(names,n); cout<<"\nsorted names\n"; show(names,n,"names"); int numbers[4]; set(numbers,3,"numbers"); cout<<"\nunsorted numbers b\n"; show(numbers,3,"numbers"); sort(numbers,3); cout<<"\nsorted numbers\n"; show(numbers,3,"numbers"); } and it compiles fine. (Note that I have changed the headers and removed the namespace). Lastly, with a little thought, I ended up using this code: (Toggle Plain Text) #include <iostream> #include <string> using std::cout; using std::cin; template<class T> void set(T p[], int num, char name){ int i; for(i=0; i<num; i++){ cout << name << "[" << i << "]="; cin >> p[i]; } } template<class T> void show(T p[], int num, char name){ int i; for(i=0; i<num; i++){ cout << name << "[" << i << "]=" << p[i] << "\n"; } } template<class T> int greater(T a, T b){return(a>b);} int greater(char a, char b){return strcmp(a,b)>0;} template<class T> void swap(T &a, T &b){ T temp = a; a = b; b = temp; } void swap(char a, char b){ char temp[20]; strcpy(temp, a); strcpy(a,b); strcpy(b,temp); } template <class T> void sort(T p[], int size){ int i,k; for(k=1;k<size;k++) for(i=0;i<size-k;i++) if (greater(p[i],p[i+1])>0){ swap(p[i],p[i+1]); } } int main(){ char names[4][21]; int n=4; set(names,n,"names"); cout<<"\nunsorted names a\n"; show(names,n,"names"); sort(names,n); cout<<"\nsorted names\n"; show(names,n,"names"); int numbers[4]; set(numbers,3,"numbers"); cout<<"\nunsorted numbers b\n"; show(numbers,3,"numbers"); sort(numbers,3); cout<<"\nsorted numbers\n"; show(numbers,3,"numbers"); } #include <iostream> #include <string> using std::cout; using std::cin; template<class T> void set(T p[], int num, char name){ int i; for(i=0; i<num; i++){ cout << name << "[" << i << "]="; cin >> p[i]; } } template<class T> void show(T p[], int num, char name){ int i; for(i=0; i<num; i++){ cout << name << "[" << i << "]=" << p[i] << "\n"; } } template<class T> int greater(T a, T b){return(a>b);} int greater(char a, char b){return strcmp(a,b)>0;} template<class T> void swap(T &a, T &b){ T temp = a; a = b; b = temp; } void swap(char a, char b){ char temp[20]; strcpy(temp, a); strcpy(a,b); strcpy(b,temp); } template <class T> void sort(T p[], int size){ int i,k; for(k=1;k<size;k++) for(i=0;i<size-k;i++) if (greater(p[i],p[i+1])>0){ swap(p[i],p[i+1]); } } int main(){ char names[4][21]; int n=4; set(names,n,"names"); cout<<"\nunsorted names a\n"; show(names,n,"names"); sort(names,n); cout<<"\nsorted names\n"; show(names,n,"names"); int numbers[4]; set(numbers,3,"numbers"); cout<<"\nunsorted numbers b\n"; show(numbers,3,"numbers"); sort(numbers,3); cout<<"\nsorted numbers\n"; show(numbers,3,"numbers"); } (note that I included the specific statements to be used from the std namespace). So i figured out it is a namespace problem. What are the commands that conflict with each other exactly? Finally, do you know of any good reference to the commands each available namespace includes? I figured out that if I want to do some serious programming, I should get involved with namespaces and templates a lot, even if my exams don't require that. __________________ Project::Soulstorm (personal homepage)

Jan 22nd, 2006, 1:43 PM	#2
Cache Hobbyist Join Date: Sep 2005 Posts: 259 Rep Power: 3	From 'stl_functions.h' which is uses the 'std' namespace: (Toggle Plain Text) /// One of the @link s20_3_3_comparisons comparison functors@endlink. template <class _Tp> struct greater : public binary_function<_Tp, _Tp, bool> { bool operator()(const _Tp& __x, const _Tp& __y) const { return __x > __y; } }; /// One of the @link s20_3_3_comparisons comparison functors@endlink. template <class _Tp> struct greater : public binary_function<_Tp, _Tp, bool> { bool operator()(const _Tp& __x, const _Tp& __y) const { return __x > __y; } }; That's conflicting with your 'greater' template function. You can either scrap the 'using namespace std' - and go for std::string (or whatever), or make your own namespace: (Toggle Plain Text) namespace MySpace { template<class T> int greater(T a, T b){return(a>b);} int greater(char a, char b){return strcmp(a,b)>0;} } template <class T> void sort(T p[], int size){ int i,k; for(k=1;k<size;k++) for(i=0;i<size-k;i++) if (MySpace::greater(p[i],p[i+1])>0){ swap(p[i],p[i+1]); } } namespace MySpace { template<class T> int greater(T a, T b){return(a>b);} int greater(char a, char b){return strcmp(a,b)>0;} } template <class T> void sort(T p[], int size){ int i,k; for(k=1;k<size;k++) for(i=0;i<size-k;i++) if (MySpace::greater(p[i],p[i+1])>0){ swap(p[i],p[i+1]); } } That still leaves: "call of overloaded `swap(int&, int&)' is ambiguous", though. I haven't messed with templates enough (yet) to suggest anything for that. EDIT: It seems to work when the whole thing is namespaced up: (Toggle Plain Text) #include <iostream> #include <string> using namespace std; namespace MySpace { template<class T> void set(T p[], int num, char name){ int i; for(i=0; i<num; i++){ cout << name << "[" << i << "]="; cin >> p[i]; } } template<class T> void show(T p[], int num, char name){ int i; for(i=0; i<num; i++){ cout << name << "[" << i << "]=" << p[i] << "\n"; } } template<class T> int greater(T a, T b){return(a>b);} int greater(char a, char b){return strcmp(a,b)>0;} template<class T> void swap(T &a, T &b){ T temp = a; a = b; b = temp; } void swap(char a, char b){ char temp[20]; strcpy(temp, a); strcpy(a,b); strcpy(b,temp); } template <class T> void sort(T p[], int size){ int i,k; for(k=1;k<size;k++) for(i=0;i<size-k;i++) if (greater(p[i],p[i+1])>0){ swap(p[i],p[i+1]); } } } int main(){ char names[4][21]; int n=4; MySpace::set(names,n,"names"); cout<<"\nunsorted names a\n"; MySpace::show(names,n,"names"); MySpace::sort(names,n); cout<<"\nsorted names\n"; MySpace::show(names,n,"names"); int numbers[4]; MySpace::set(numbers,3,"numbers"); cout<<"\nunsorted numbers b\n"; MySpace::show(numbers,3,"numbers"); MySpace::sort(numbers,3); cout<<"\nsorted numbers\n"; MySpace::show(numbers,3,"numbers"); } #include <iostream> #include <string> using namespace std; namespace MySpace { template<class T> void set(T p[], int num, char name){ int i; for(i=0; i<num; i++){ cout << name << "[" << i << "]="; cin >> p[i]; } } template<class T> void show(T p[], int num, char name){ int i; for(i=0; i<num; i++){ cout << name << "[" << i << "]=" << p[i] << "\n"; } } template<class T> int greater(T a, T b){return(a>b);} int greater(char a, char b){return strcmp(a,b)>0;} template<class T> void swap(T &a, T &b){ T temp = a; a = b; b = temp; } void swap(char a, char b){ char temp[20]; strcpy(temp, a); strcpy(a,b); strcpy(b,temp); } template <class T> void sort(T p[], int size){ int i,k; for(k=1;k<size;k++) for(i=0;i<size-k;i++) if (greater(p[i],p[i+1])>0){ swap(p[i],p[i+1]); } } } int main(){ char names[4][21]; int n=4; MySpace::set(names,n,"names"); cout<<"\nunsorted names a\n"; MySpace::show(names,n,"names"); MySpace::sort(names,n); cout<<"\nsorted names\n"; MySpace::show(names,n,"names"); int numbers[4]; MySpace::set(numbers,3,"numbers"); cout<<"\nunsorted numbers b\n"; MySpace::show(numbers,3,"numbers"); MySpace::sort(numbers,3); cout<<"\nsorted numbers\n"; MySpace::show(numbers,3,"numbers"); } Last edited by Cache; Jan 22nd, 2006 at 1:53 PM.

Jan 22nd, 2006, 2:36 PM	#3
Soulstorm Hobbyist Programmer Join Date: Jan 2006 Location: Menidi, Athens, Greece Posts: 234 Rep Power: 3	Thanks a lot! So, I figured right. Because it was an examination exercise, I decided to keep the code as unchanged as I could, so I have written this code: (Toggle Plain Text) #include <iostream> #include <string> using std::cout; using std::cin; template<class T> void set(T p[], int num, char name){ int i; for(i=0; i<num; i++){ cout << name << "[" << i << "]="; cin >> p[i]; } } template<class T> void show(T p[], int num, char name){ int i; for(i=0; i<num; i++){ cout << name << "[" << i << "]=" << p[i] << "\n"; } } template<class T> int greater(T a, T b){return(a>b);} int greater(char a, char b){return strcmp(a,b)>0;} template<class T> void swap(T &a, T &b){ T temp = a; a = b; b = temp; } void swap(char a, char b){ char temp[20]; strcpy(temp, a); strcpy(a,b); strcpy(b,temp); } template <class T> void sort(T p[], int size){ int i,k; for(k=1;k<size;k++) for(i=0;i<size-k;i++) if (greater(p[i],p[i+1])>0){ swap(p[i],p[i+1]); } } int main(){ char names[4][21]; int n=4; set(names,n,"names"); cout<<"\nunsorted names a\n"; show(names,n,"names"); sort(names,n); cout<<"\nsorted names\n"; show(names,n,"names"); int numbers[4]; set(numbers,3,"numbers"); cout<<"\nunsorted numbers b\n"; show(numbers,3,"numbers"); sort(numbers,3); cout<<"\nsorted numbers\n"; show(numbers,3,"numbers"); } #include <iostream> #include <string> using std::cout; using std::cin; template<class T> void set(T p[], int num, char name){ int i; for(i=0; i<num; i++){ cout << name << "[" << i << "]="; cin >> p[i]; } } template<class T> void show(T p[], int num, char name){ int i; for(i=0; i<num; i++){ cout << name << "[" << i << "]=" << p[i] << "\n"; } } template<class T> int greater(T a, T b){return(a>b);} int greater(char a, char b){return strcmp(a,b)>0;} template<class T> void swap(T &a, T &b){ T temp = a; a = b; b = temp; } void swap(char a, char b){ char temp[20]; strcpy(temp, a); strcpy(a,b); strcpy(b,temp); } template <class T> void sort(T p[], int size){ int i,k; for(k=1;k<size;k++) for(i=0;i<size-k;i++) if (greater(p[i],p[i+1])>0){ swap(p[i],p[i+1]); } } int main(){ char names[4][21]; int n=4; set(names,n,"names"); cout<<"\nunsorted names a\n"; show(names,n,"names"); sort(names,n); cout<<"\nsorted names\n"; show(names,n,"names"); int numbers[4]; set(numbers,3,"numbers"); cout<<"\nunsorted numbers b\n"; show(numbers,3,"numbers"); sort(numbers,3); cout<<"\nsorted numbers\n"; show(numbers,3,"numbers"); } Anyway, last question still unanswered, have you got any online references to namespaces? How am I supposed to know which commands confront others in certain namespaces? __________________ Project::Soulstorm (personal homepage)

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C++ template and namespace question