function overloading

When I compile the included code with the Borland c++ 5.5 command line tools I get the error:

Quote:

---

C:\BC45\bob>bcc32 over1.cpp
Borland C++ 5.5.1 for Win32 Copyright (c) 1993, 2000 Borland
OVER1.CPP:
Error E2015 OVER1.CPP 13: Ambiguity between 'std::abs(int)' and 'abs(int)' in fu
nction main()
Warning W8004 OVER1.CPP 20: 'i' is assigned a value that is never used in functi
on main()
*** 1 errors in Compile ***

---

Why?

Also, when I compile it with Borland C++ 4.5 it rounds 64.53 upto 65 when instead it should output 64.53. Isn't setprecision() used for specifying how many decimal places you want? Like in C you could say printf("%.2f");.

Code:

---

#include <iostream>
#include <iomanip.h>

int abs(int i);
float abs(float x);
int main()
{
  int ians;
  float fans;
  int i = -15;
  float x = -64.53;

  ians = abs(i);
  cout << "Integer absolute value of -15 is " << ians << endl;

  fans = abs(x);
  cout << "Float absolute value of -64.53 is " << setprecision(2) << fans << endl;
  cin.get();
  return 0;
}

int abs(int i)
{
  if(i < 0)
      return(i * -1);
  else
      return (i);
}

float abs(float x)
{
  if(x < 0.0)
      return(x * -1.00);
  else
      return (x);
}

---

put a "using namespace std;" in there under the headers


Also, naming a function the same as an STD fxn is not a good idea - create a namespace around your functions and everything should be good.

Code:

---

namespace myMath{
int abs(int i);
float abs(float x);
}

.......

int myMath::abs(int i)
{
  if(i < 0)
      return(i * -1);
  else
      return (i);
}

float myMath::abs(float x)
{
  if(x < 0.0)
      return(x * -1.00);
  else
      return (x);
}

---

Or...if you want to use your functions glabally, add the global namespace specifire when you call

ians = ::abs(i);

Instead all this, just stick to the old standard and put:

Code:

---

#include<iostream.h>  // with .h ending

---

also get rid of the line

Code:

---

precision(2);

---

and to get rid of all the warnings use 'double' instead of 'float' to avoid any data loss, i.e. (0.0 is a 'double')


good luck

matheo917

iostream.h is like you said, old. it will produce warnings on newer compilers, just mentioning if you decide to use it.