Currently we are using GlassMapper V3 and CastleWindsor in our project. We would like to upgrade it to V4 for performance and use structure map IOC instead of CastleWindsor.
Not sure how to make GlassMapper to use structure IOC. Any help on this would be great.
Glass Mapper no longer has a dependency on Castle Windsor in version 4 (or any 3rd party IoC container), you can remove it and use whatever IoC container you like: http://glass.lu/Blog/GlassV4
Make sure you register your container in the Sitecore
initialize
pipeline (see this example using Autofac) and you should consider using a chained dependency resolver so that Sitecore's Dependency Resolver continues to resolve and work correctly.