How to fix: error: invalid conversion from 'const MyClass' to 'MyClass'

Question

I am getting this compile error:

error: invalid conversion from 'const MyClass*' to 'MyClass*'

Here is the code:

std::tr1::shared_ptr<MyClass> myClassA;
const MyClass* myClassB;
myClassA = std::tr1::shared_ptr<MyClass>(myClassB); // error here

I think I understand the error, just don't know how to fix. I need myClassB to be a const so how to convert/copy classB to a shared_ptr?

score 8 · Accepted Answer · answered Jul 14 '12 at 15:00

8

You'll need a shared pointer to a const object:

std::tr1::shared_ptr<const MyClass> myClassA;
                     ^^^^^

answered Jul 14 '12 at 15:00

Mike Seymour

score 0 · Answer 2 · edited Jul 14 '12 at 15:16

0

You can't go from a const MyClass to MyClass.

myClassA = std::tr1::shared_ptr< **const** MyClass>(myClassB);

edited Jul 14 '12 at 15:16

Luchian Grigore

answered Jul 14 '12 at 15:02

Caesar

1

In a language where `*` has meaning it is awkward to use it for emphasis. You could use Clang's way of indicating bits by underlining with `^~~~~` for example. – Matthieu M. Jul 14 '12 at 16:08
@Matthieu M I know that, I wanted that part to be bold but you can't bold something when it is in a code. So I didn't put it in code but my editor decided to put it in code. – Caesar Jul 14 '12 at 16:17

2 Answers2