• tcak (4/4) May 22 2015 I know there is mutable variables, but what is a mutable method?
• FreeSlave (5/9) May 22 2015 The method that can change the state of the object.
• Steven Schveighoffer (3/7) May 22 2015 English grammar nit: I would say mutating instead of mutable.
• Jonathan M Davis via Digitalmars-d-learn (19/23) May 22 2015 It's a method / member function which is not const or immutable. e.g.

"tcak" <tcak gmail.com> writes:

I know there is mutable variables, but what is a mutable method?

Error message says "mutable method 
project.mariadb.connector.ver2p1.resultset.ResultSetColumn.info 
is not callable using a const object".

"FreeSlave" <freeslave93 gmail.com> writes:

On Friday, 22 May 2015 at 12:12:46 UTC, tcak wrote:
 I know there is mutable variables, but what is a mutable method?

 Error message says "mutable method 
 project.mariadb.connector.ver2p1.resultset.ResultSetColumn.info 
 is not callable using a const object".

The method that can change the state of the object.
This kind of error says that you try to call non-const method on 
const object, which is prohibited. You can call only the methods 
marked as const on the const object.

Steven Schveighoffer <schveiguy yahoo.com> writes:

On 5/22/15 8:12 AM, tcak wrote:
 I know there is mutable variables, but what is a mutable method?

 Error message says "mutable method
 project.mariadb.connector.ver2p1.resultset.ResultSetColumn.info is not
 callable using a const object".

English grammar nit: I would say mutating instead of mutable.

-Steve

Jonathan M Davis via Digitalmars-d-learn writes:

On Friday, May 22, 2015 12:12:45 tcak via Digitalmars-d-learn wrote:
 I know there is mutable variables, but what is a mutable method?

 Error message says "mutable method
 project.mariadb.connector.ver2p1.resultset.ResultSetColumn.info
 is not callable using a const object".

It's a method / member function which is not const or immutable. e.g.

struct MyStruct
{
    void foo() {}  // This method is mutable
    void bar() const {}
    void baz() immutable {}
}

What it's really indicating is the constness of the object's this point is
inside the function. So, you can only call a mutable method on a mutable
object, because otherwise, you'd be converting a const or immutable
reference or pointer to mutable, which would violate the type system.
mutable and immutable can be converted to const, but mutable and const
can't be converted to immutable, and const and immutable can't be converted
to mutable.

So, in your case, it sounds like you're trying to call a mutable method on a
const object, which won't work. The method needs to be const, since the
object is const.

- Jonathan M Davis