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Apr 13th, 2002, 02:52 AM
#1
Thread Starter
Hyperactive Member
Is macros necessary in C++?
My question here is "Is macros a more of the C thingy? Is the use of macros encouraged in C++ where the same thing can be done in plain code?" Here's I am not talking about the use of macros in preprocessor headers but macros in source code.
Here 's an extract from MSDN
Code:
#include <stdio.h>
#define EPSILON 0.0001 // Define your own tolerance
#define FLOAT_EQ(x,v) (((v - EPSILON) < x) && (x <( v + EPSILON)))
void main()
{
float a,b,c
a=1.345f;
b=1.123f;
c=a+b;
//if (FLOAT_EQ(c, 2.468)) // Remove comment for correct result
if (c == 2.468) //Comment this line for correct result
printf("They are equal\n");
else
printf("They are not equal!!The value of c is %13.10f,or %f",c,c);
}
I can understand the above code very well. There were some macros that I was browsing some time ago, that I cannot understand fully. However I understand the logic of the source and macros(what they are trying to do.).
If I were to implement that source myself, I will turn that macros into my plain code as I still do not understand fully how macros worked.
However the main question is "Is macros necessary and encouraged in C++?"
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Apr 13th, 2002, 06:50 AM
#2
Monday Morning Lunatic
No, not particularly.
Both of those could be implemented differently:
Code:
#include <stdio.h>
const double EPSILON = 0.0001; // Define your own tolerance
inline bool FLOAT_EQ(double x, double v) {
return (((v - EPSILON) < x) && (x <( v + EPSILON)));
}
void main()
{
float a,b,c
a=1.345f;
b=1.123f;
c=a+b;
//if (FLOAT_EQ(c, 2.468)) // Remove comment for correct result
if (c == 2.468) //Comment this line for correct result
printf("They are equal\n");
else
printf("They are not equal!!The value of c is %13.10f,or %f",c,c);
}
Macros are almost unnecessary now with templates and inline functions - the preprocessor should only really be used for conditionally including blocks of code.
I refuse to tie my hands behind my back and hear somebody say "Bend Over, Boy, Because You Have It Coming To You".
-- Linus Torvalds
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