-- Operator overloading example ---- importing ---- if string.sub(_VERSION,1,7)=='Lua 5.0' then -- lua5.0 doesnt have a nice way to do this lib=loadlib('example.dll','luaopen_example') or loadlib('example.so','luaopen_example') assert(lib)() else -- lua 5.1 does require('example') end print "ok, let's test Lua's ownership of C++ objects" print("Currently there are",example.Shape_nshapes,"shapes (there should be 0)") print "\nLet's make a couple" a=example.Square(10) b=example.Circle(1) print("Currently there are",example.Shape_nshapes,"shapes (there should be 2)") print "\nNote let's use the createX functions" c=example.createCircle(5) d=example.createSquare(3) print("Currently there are",example.Shape_nshapes,"shapes (there should be 4)") print "\nWe will run the garbage collector & see if they are till here" collectgarbage() print("Currently there are",example.Shape_nshapes,"shapes (there should be 4)") print "\nLet's get rid of them all, collect garbage & see if they are till here" a,b,c,d=nil,nil,nil,nil collectgarbage() print("Currently there are",example.Shape_nshapes,"shapes (there should be 0)") print "\nLet's start putting stuff into the ShapeOwner" print "The ShapeOwner now owns the shapes, but Lua still has pointers to them" o=example.ShapeOwner() a=example.Square(10) b=example.Circle(1) o:add(a) o:add(b) o:add(example.createSquare(5)) print("Currently there are",example.Shape_nshapes,"shapes (there should be 3)") print "\nWe will nil our references,run the garbage collector & see if they are still here" print "they should be, as the ShapeOwner owns them" a,b=nil,nil collectgarbage() print("Currently there are",example.Shape_nshapes,"shapes (there should be 3)") print "\nWe will access them and check that they are still valid" a=o:get(0) b=o:get(1) print(" Area's are",a:area(),b:area(),o:get(2):area()) collectgarbage() print("Currently there are",example.Shape_nshapes,"shapes (there should be 3)") print "\nWe will remove one from the C++ owner & pass its ownership to Lua," print " then check that they are still unchanged" a,b=nil,nil a=o:remove(0) -- a now owns it collectgarbage() print("Currently there are",example.Shape_nshapes,"shapes (there should be 3)") print "\nDelete the ShapeOwner (this should destroy two shapes)," print " but we have one left in Lua" o=nil collectgarbage() print("Currently there are",example.Shape_nshapes,"shapes (there should be 1)") print "\nFinal tidy up " a=nil collectgarbage() print("Currently there are",example.Shape_nshapes,"shapes (there should be 0)") print "Final test, we will create some Shapes & pass them around like mad" print "If there is any memory leak, you will see it in the memory usage" io.flush() sh={} -- make some objects for i=0,10 do a=example.Circle(i) b=example.Square(i) sh[a]=true sh[b]=true end o=example.ShapeOwner() for i=0,10000 do for k,_ in pairs(sh) do o:add(k) end sh={} -- clear it while true do a=o:remove(0) if a==nil then break end sh[a]=true end if i%100==0 then collectgarbage() end end print "done" o,sh=nil,nil collectgarbage() print("Currently there are",example.Shape_nshapes,"shapes (there should be 0)") print "that's all folks!"