Andrey Semashev
On Wednesday, 4 May 2016 17:01:49 MSK Walt Karas wrote:
In C++, a default assignment operator is generated for a class if all of its components (data members and base classes) have an assignment operator. There are plans in C++17 to do something similar for comparison operators. This header, in https://github.com/wkaras/C-plus-plus-library-default-operators , facilitates that, more generally, if there is an operation on all the components of a class, a single macro invocation can provide this operation on the class as well. A big drawback is that it's very intrusive into the class definition. Each class component must be defined using a macro, COMPOSITE_OP_MBR_T(int) i; for examle. The class will in truth be a template, with the template parameter being defaulted for normal usage. I don't know which, if any, existing Boot library this header would belong in.
I think, Boost.Fusion already provides this for all adapted types.
http://www.boost.org/doc/libs/1_60_0/libs/fusion/doc/html/fusion/sequence/ operator/comparison.html
Yes, but there is not full overlap of the capabilities. Fusion doesn't seem to provide a way to define a class with access control, base classes, and member functions as a sequence. I'm assuming BOOST_FUSION_DEFINE_STRUCT has no runtime overhead, although I could not find and explicit statement to that effect.