Hi everyone, I am facing a "design" issue while sharing error_codes across modules boundaries. Has I understand the design, error_categories like "generic_error_category" are static (maybe to provide unique way to represent error_category, avoiding error_category ID confilct, and allowing users to extend with there own categories). The question is : How can we share error_code across modules (A and B), when these modules are both statically linked with there own boost::system library (same version)? Under Windows operating system, both static version of boost::system library co-exist in the same process address space (that contains module A and module B), they do not share code or static data members. Comparison between error_code is made by looking error_value and error_category, but error_categroy doesn't has the same "static" address, causing comparison to fail, even when the semantic is respected (because of the co-existing static error_category with different address). sharing the boost::system has a unique shared library used by both module A and B could solve this issue, but this solution is not suitable for certain needs. Thanks for your help! -- Amoriello Hutti