Useful Header(maybe) C++

[Fireking300]

Here is a header that I have created. Any more ideas would be great or optimizing the current code would be better.

#ifdef WIN32
	#include <windows.h>
#endif
#include <iostream>
#include <ctime>
#include <cstdio>
#include <cstdlib>
#include <cstring>
using namespace std;

void dans_sleep(double seconds)
{
	
	#ifdef WIN32
		sleep(seconds * 1000);
	#else
		usleep(seconds * 1000000);
	#endif
}

void dans_clear(double seconds)
{
	#ifdef WIN32
		dans_sleep(seconds);
		system("cls");
	#else
		dans_sleep(seconds);
		system("clear");
	#endif
}

void dans_clear()
{
	#ifdef WIN32
		system("cls");
	#else
		system("clear");
	#endif
}

void dans_pause()
{
	cout << "Please hit enter to continue...";
	cin.get();
}


void dans_swap(int &a, int &b)
{
	int temp = a;
	a = b;
	b = temp;
}

void dans_swap(char &a, char &b)
{
	char temp = a;
	a = b;
	b = temp;
}

void dans_swap(double &a, double &b)
{
	double temp = a;
	a = b;
	b = temp;
}

void dans_swap(float &a, float &b)
{
	float temp = a;
	a = b;
	b = temp;
}

void dans_ascii(char *world, int width, int height)
{ 
    for(int a = 0; a < height; a++)
    {
        for(int b = 0; b < width; b++)
        {
            cout << *(world + (a * width) + b);
        }
        cout << endl;
    }
}

void dans_gotoxy(int x, int y) 
{
	#ifdef WIN32
		COORD coord;
		coord.X = x;
		coord.Y = y;
		SetConsoleCursorPosition(GetStdHandle(STD_OUTPUT_HANDLE), coord);
	#else
		char essq[100];
		char xstr[100];
		char ystr[100];	
		sprintf(xstr, "%d", x);
		sprintf(ystr, "%d", y);
		essq[0] = '\0';
		strcat(essq, "\033[");
		strcat(essq, ystr);
		strcat(essq, "d");
		strcat(essq, "\033[");
		strcat(essq, xstr);
		strcat(essq, "G");
		printf("%s", essq);
	#endif
}

[flo8464]

1. Don't use sytem("cls"). It has an incredible overhead. Use your dans_gotoxy and simply overwrite the console buffer with spaces.

2. Your swap functions could be generic by using templates.

This is a generic one, works with every type:

template<typename T>
void dans_swap(T& a, T& b)
{
	T temp = a;
	a = b;
	b = temp;
}

3. Headers of the C-Library don't have the suffix .h anymore, instead they have the prefix c. For example <stdio.h> becomes <cstdio>

4. This leads to the next point ... don't use C-Libraries, if there are C++ solutions

[Cypher]

Here is a header that I have created. Any more ideas would be great or optimizing the current code would be better.

#ifdef WIN32
	#include <windows.h>
#endif
#include <iostream>
#include <ctime>
#include <cstdio>
#include <cstdlib>
#include <cstring>
using namespace std;

void dans_sleep(double seconds)
{
	
	#ifdef WIN32
		sleep(seconds * 1000);
	#else
		usleep(seconds * 1000000);
	#endif
}

void dans_clear(double seconds)
{
	#ifdef WIN32
		dans_sleep(seconds);
		system("cls");
	#else
		dans_sleep(seconds);
		system("clear");
	#endif
}

void dans_clear()
{
	#ifdef WIN32
		system("cls");
	#else
		system("clear");
	#endif
}

void dans_pause()
{
	cout << "Please hit enter to continue...";
	cin.get();
}


void dans_swap(int &a, int &b)
{
	int temp = a;
	a = b;
	b = temp;
}

void dans_swap(char &a, char &b)
{
	char temp = a;
	a = b;
	b = temp;
}

void dans_swap(double &a, double &b)
{
	double temp = a;
	a = b;
	b = temp;
}

void dans_swap(float &a, float &b)
{
	float temp = a;
	a = b;
	b = temp;
}

void dans_ascii(char *world, int width, int height)
{ 
    for(int a = 0; a < height; a++)
    {
        for(int b = 0; b < width; b++)
        {
            cout << *(world + (a * width) + b);
        }
        cout << endl;
    }
}

void dans_gotoxy(int x, int y) 
{
	#ifdef WIN32
		COORD coord;
		coord.X = x;
		coord.Y = y;
		SetConsoleCursorPosition(GetStdHandle(STD_OUTPUT_HANDLE), coord);
	#else
		char essq[100];
		char xstr[100];
		char ystr[100];	
		sprintf(xstr, "%d", x);
		sprintf(ystr, "%d", y);
		essq[0] = '\0';
		strcat(essq, "\033[");
		strcat(essq, ystr);
		strcat(essq, "d");
		strcat(essq, "\033[");
		strcat(essq, xstr);
		strcat(essq, "G");
		printf("%s", essq);
	#endif
}

If that's a header file there are quite a few problems.

1. You're defining functions in your header that have external linkage. This will cause multiple-definition linker errors. Mark them as inline if you really want to define them in a header.
2. Never never never never never NEVER put a using declaration in a header file. That causes pollution in every file that includes your header.
3. Your swap functions are useless.
4. Your pause function will not work if the stream is in an invalid state. Clear and sync the stream before calling istream::get.
5. Your sleep function won't compile because you haven't included the appropriate header for non-windows platforms. At any rate, that's a really disgusting solution because you assume that the function 'usleep' is available for all non-windows platforms, which afaik is wrong. If you want cross-platform threading just use Boost.Thread (that will also make it easier to transition to C++0x's threading library as Boost.Thread was used as a 'base').
6. Your 'clear' function suffers from the same cross-platform problem (not to mention that using 'system' to implement it is about as yuck as you can get).
7. dans_ascii is a very unsafe function. STL strings are there for a reason. Use them.
8. I don't even want to know what gotoxyz does.

1. Don't use sytem("cls"). It has an incredible overhead. Use your dans_gotoxy and simply overwrite the console buffer with spaces.

2. Your swap functions could be generic by using templates.

This is a generic one, works with every type:

template<typename T>
void dans_swap(T& a, T& b)
{
	T temp = a;
	a = b;
	b = temp;
}

3. Headers of the C-Library don't have the suffix .h anymore, instead they have the prefix c. For example <stdio.h> becomes <cstdio>

4. This leads to the next point ... don't use C-Libraries, if there are C++ solutions

Errr, speaking of there being C++ solutions:
swap

There's no need to re-implement swap at all unless you're going to be doing work that is specific to a given type. The STL provides a generic implementation for a reason.

Also, your implementation is "wrong" anyway because it uses the assignment operator rather than the constructor to create the temporary object. That's unnecessary overhead as it results in one constructor call and then one assignment operator call, rather than just a constructor call.

[Fireking300]

Thank you for the suggestions I will work right away to rectify these issues.