Re: Does not compile
on nov 2, 8:32 pm, andrey tarasevich <andreytarasev...@hotmail.com>
wrote:
parag_p...@hotmail.com wrote:
#include <iostream>
using namespace std;
void ha(int& j);
void ha(int& j) {
cout <<j<<endl;
}
main()
int main()
{
int j = 0;
ha(null);
}
why so ,
gcc version 3.3.6
p236.cc: in function `int main()':
p236.cc:14: error: invalid initialization of non-const reference of
type 'int&'
from a temporary of type 'long int'
p236.cc:6: error: in passing argument 1 of `void ha(int
'null' is a substitute for and integral constant expression of
value 0. it is not an lvalue.
it can be, but then it must have a const type, and cannot bind
to a non-const reference either.
[...]
it is worth noting though, that null macro should normally be
used in pointer context and using it in place of an 'int'
value is not a good practice.
Good compilers warn if NULL is used in a non-pointer context,
e.g.:
$ cat null.cc
#include <cstddef>
int
main()
{
int i = NULL ;
return 0 ;
}
$ g++ null.cc
null.cc: In function 'int main()':
null.cc:6: warning: converting to non-pointer type 'int' from NULL
--
James Kanze (GABI Software) email:james.kanze@gmail.com
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