Build error for static_cast of btCollisionObject*

[xman]

Hi, I'm trying to build bullet 2.81 with my simulator code which is based on VTK 5.10 + QT4.

I have been used bullet 2.80, and had no problem with my code. But after installing to bullet 2.81, I got a build problem with my code. The error said

' error: static_cast from type 'const btCollisionObject*' to type 'btCollisionObject*' casts away qualifiers '

The code is

Code: Select all

int numManifolds =  discreteTimeStepWorld->getDispatcher()->getNumManifolds();
	for (i=0;i<numManifolds;i++)
	{
		btPersistentManifold* contactManifold = discreteTimeStepWorld->getDispatcher()->getManifoldByIndexInternal(i);
		btCollisionObject* obA = static_cast<btCollisionObject*>(contactManifold->getBody0());
		btCollisionObject* obB = static_cast<btCollisionObject*>(contactManifold->getBody1());
                 ...
          }

And basically same with the demo 'CollisionInterfaceDemo'. The demo is compiled and working well, but not my codes.

Environment: 32 bit, intel, ubuntu 12.04

Any idea?

[Empire-Phoenix]

Did you try to put in a -fpermissive?

[Granyte]

i had to replace it with a const cast in 2.81

[xman]

Unfortunately, I already tried const_cast, and it did not work. Apparently, some of the member functions in btCollisionObject are changed to const member function in bullet 2.81. I just solved the problem by modifying 'static_cast<btCollisionObject*>' to '(btCollisionObject*)'. But, I don't know why const_cast didn't work for me.

[Jonathan]

I'm also running into the same error here. Casting away the const can't be the intended use. Can we get Erwin to explain what the change was about here?

Thanks.

[marios]

I think you just don't need casting, because getBody() in bullet 2.81 returns btCollisionObject* instead void* which was in previous bullet versions. So it should be just:

btCollisionObject* obA = contactManifold->getBody0();
or
const btCollisionObject* obA = contactManifold->getBody0();

[Jonathan]

I think you just don't need casting, because getBody() in bullet 2.81 returns btCollisionObject* instead void* which was in previous bullet versions. So it should be just:

btCollisionObject* obA = contactManifold->getBody0();
or
const btCollisionObject* obA = contactManifold->getBody0();

Ah yes, this makes sense. Derp! Can't believe I missed that. Should I go ahead and edit the wiki (http://bulletphysics.org/mediawiki-1.5. ... d_Triggers) to reflect the proper line of code?

Code: Select all

const btCollisionObject* obA = contactManifold->getBody0();
const btCollisionObject* obB = contactManifold->getBody1();