Article 2: Macro VS Inline Function. There can be ‘n’ number of cases where macro will fail. I
will try to demonstrate few of them.
#define
MIN_VERSION_1(a,b) a < b ? a : b
#define
MIN_VERSION_2(a,b) (a) < (b) ? (a) : (b)
#define
MIN_VERSION_3(a,b) ( (a) < (b) ? (a) : (b) )
inline int min_function(int
a ,int b)
{
return ( a
< b ? a : b );
}
All
the use cases will be checked on the above code snippet.
Consideration:
1.
Let’s consider we have two variables with name a,b and we have to find min from
them.
int a =
10;
int b =
20;
int min =
0;
2.
I have created one method to print the result in little good manner, you can
write your own. The function is written in just for formatted
output.
#define
MAX_STRING_LENGTH 45
#define WIDTH
4
void
printResult(const char* useCase, int
a, int b,int
min, bool pass)
{
std::cout<<"\n";
std::cout<<" | "<<useCase;
// Extra padding
for good output.
int lk =
std::strlen(useCase);
for(int i = 0 ; i < abs(MAX_STRING_LENGTH -
std::strlen(useCase)); i++)
{
std::cout<<" ";
}
std::cout<<std::setw(WIDTH)<<" |
" <<a;
std::cout<<std::setw(WIDTH)<<" |
" <<b;
std::cout<<std::setw(WIDTH)<<" |
" <<min;
std::cout<<std::setw(WIDTH)<<" |
" <<( pass ? " PASS | " :"
FAIL | ");
}
void
printResult(const char* useCase, const
char* a, const
char* b,const
char* min, const char*
result)
{
std::cout<<"\n";
std::cout<<" | "<<useCase;
// Extra padding
for good output.
int lk =
std::strlen(useCase);
for(int i = 0 ; i < abs(MAX_STRING_LENGTH -
std::strlen(useCase)); i++)
{
std::cout<<" ";
}
std::cout<<std::setw(WIDTH)<<" |
" <<a;
std::cout<<std::setw(WIDTH)<<" |
" <<b;
std::cout<<std::setw(WIDTH)<<" |
" <<min;
std::cout<<std::setw(WIDTH -
1)<<" | "
<<result;
}
3.
A function is created for resetting the values to default
values:
void
resetValues(int&a, int&b, int
&min)
{
a = 10;
b = 20;
min = 0;
}
Case
1:
std::cout<<"\n\n------------------------------------------------";
std::cout<<"\n\t\tFinding output for min( a,
b)";
std::cout<<"\n--------------------------------------------------";
printResult("Use Case","a
","b ","min","Result
|");
std::cout<<"\n--------------------------------------------------";
resetValues(a,b,min);
min = min_function(a
,b);
printResult("Expected",a,b,min,1);
resetValues(a,b,min);
min = MIN_VERSION_1(a
,b);
printResult("MIN_VERSION_1(a,b) a < b ? a :
b",a,b,min,1);
resetValues(a,b,min);
min = MIN_VERSION_2(a
,b);
printResult("MIN_VERSION_2(a,b) (a) < (b) ? (a) :
(b)",a,b,min,1);
resetValues(a,b,min);
min = MIN_VERSION_3(a
,b);
printResult("MIN_VERSION_3(a,b) ( (a) < (b) ? (a) : (b)
)",a,b,min,1);
Output:
Case
2:
std::cout<<"\n\n------------------------------------------------";
std::cout<<"\n\t\tFinding output for min( a += 3,
b)";
std::cout<<"\n--------------------------------------------------";
printResult("Use Case","a
","b ","min","Result
|");
std::cout<<"\n--------------------------------------------------";
resetValues(a,b,min);
min = min_function(a +=3
,b);
printResult("Expected",a,b,min,1);
resetValues(a,b,min);
min = MIN_VERSION_1(a +=3
,b);
printResult("MIN_VERSION_1(a,b) a < b ? a :
b",a,b,min,0);
resetValues(a,b,min);
min = MIN_VERSION_2(a +=3
,b);
printResult("MIN_VERSION_2(a,b) (a) < (b) ? (a) :
(b)",a,b,min,0);
resetValues(a,b,min);
min = MIN_VERSION_3(a +=3
,b);
printResult("MIN_VERSION_3(a,b) ( (a) < (b) ? (a) : (b)
)",a,b,min,0);
Output:
Case
3:
std::cout<<"\n\n------------------------------------------------";
std::cout<<"\n\t\tFinding output for min( a , b) +
25";
std::cout<<"\n--------------------------------------------------";
printResult("Use Case","a
","b ","min","Result
|");
std::cout<<"\n--------------------------------------------------";
resetValues(a,b,min);
min = min_function(a ,b) +
25;
printResult("Expected",a,b,min,1);
resetValues(a,b,min);
min = MIN_VERSION_1(a ,b) +
25;
printResult("MIN_VERSION_1(a,b) a < b ? a :
b",a,b,min,0);
resetValues(a,b,min);
min = MIN_VERSION_2(a ,b) +
25;
printResult("MIN_VERSION_2(a,b) (a) < (b) ? (a) :
(b)",a,b,min,0);
resetValues(a,b,min);
min = MIN_VERSION_3(a ,b) +
25;
printResult("MIN_VERSION_3(a,b) ( (a) < (b) ? (a) : (b)
)",a,b,min,1);
Output:
Case
4:
std::cout<<"\n\n------------------------------------------------";
std::cout<<"\n\t\tFinding output for min( ++a ,
b)";
std::cout<<"\n--------------------------------------------------";
printResult("Use Case","a
","b ","min","Result
|");
std::cout<<"\n--------------------------------------------------";
resetValues(a,b,min);
min = min_function( ++a ,
b);
printResult("Expected",a,b,min,1);
resetValues(a,b,min);
min = MIN_VERSION_1( ++a ,
b);
printResult("MIN_VERSION_1(a,b) a < b ? a :
b",a,b,min,0);
resetValues(a,b,min);
min = MIN_VERSION_2( ++a ,
b);
printResult("MIN_VERSION_2(a,b) (a) < (b) ? (a) :
(b)",a,b,min,0);
resetValues(a,b,min);
min = MIN_VERSION_3( ++a ,
b);
printResult("MIN_VERSION_3(a,b) ( (a) < (b) ? (a) : (b)
)",a,b,min,0);
Output:
