template <typename T>
struct Test {
Test& operator<<(const T* &x) {
printf(" << %d",*x);
return *this;
}
};
Test<int> test;
...
int a=2,b=3,c=4;
test << &a << &b << &c //I saw Qt using this style in their assistant...
Bitwise-shift operator with pointers and templates - Compiler Error
Author
I'm getting a compiler error that I do not know how to fix, and do not really understand why I'm getting it.
Here's the basic code:
You want something like:
- Passing x by reference is unnecessary.
- It was failing because the address-of operator returns a constant pointer.
[edit: You could also do it by reference, but the calling code would change:
jfl.
Test& operator<<( T const * const x ) { printf(" << %d",*x); return *this;}- Passing x by reference is unnecessary.
- It was failing because the address-of operator returns a constant pointer.
[edit: You could also do it by reference, but the calling code would change:
Test& operator<<( T const &x ) { printf(" << %d",x); return *this;}// ...int a = 2, b = 3, c = 4;test << a << b << c;jfl.
Certainly. In C++, you essentially read types from right to left. So:
int * const is a const pointer to an int.
int const * is a pointer to a const int.
int const * const is a const pointer to a const int.
const int * and int const * are equivalent.
So are const int and int const.
Does that help?
Read my above edit, by the way. You may prefer that method.
int * const is a const pointer to an int.
int const * is a pointer to a const int.
int const * const is a const pointer to a const int.
const int * and int const * are equivalent.
So are const int and int const.
Does that help?
Read my above edit, by the way. You may prefer that method.
Author
Well, I decided not to make it constant because it conflicted with other functions, and dropped the referencing to a pointer, since it was only a pointer.
Plus, I'm going to add that other operator overload. Thanks!
Plus, I'm going to add that other operator overload. Thanks!
This topic is closed to new replies.
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