c++ - MemoryOutputStream is not a member of PxToolkit -

i'm trying create physx actor w/ custom mesh., following official doc:

static const pxvec3 convexverts[] = {pxvec3(0,1,0),pxvec3(1,0,0),pxvec3(-1,0,0),pxvec3(0,0,1),pxvec3(0,0,-1)};   pxconvexmeshdesc convexdesc; convexdesc.points.count     = 5; convexdesc.points.stride    = sizeof(pxvec3); convexdesc.points.data      = convexverts; convexdesc.flags            = pxconvexflag::ecompute_convex; convexdesc.vertexlimit      = 256;  pxtoolkit::memoryoutputstream buf; if(!cooking.cookconvexmesh(convexdesc, buf))     return null; pxtoolkit::memoryinputdata input(buf.getdata(), buf.getsize()); pxconvexmesh* convexmesh = thephysics->createconvexmesh(input); pxshape* aconvexshape = aconvexactor->createshape(pxconvexmeshgeometry(convexmesh), amaterial); 

taken the official docs.

but when try compile:

error c2039: 'memoryoutputstream' is not member of pxtoolkit. 

i've included pxtoolkit.lib file manually built using vs 2013,as headers. , indeed mos not in pxtkstream.cpp.