Question 1

How to serialize a struct to JSON with visit_struct?

Accepted Answer

Implement a visitor that outputs each field as a key-value pair; use for_each with a lambda in C++14 to iterate over members and build a JSON object, similar to the debugging example in the README.

Question 2

visit_struct vs Boost.Hana: which should I use?

Accepted Answer

Choose visit_struct for lightweight, dependency-free reflection on older C++11 compilers; Boost.Hana is better for C++14+ projects needing more advanced metaprogramming features, but has stricter compiler requirements.

Question 3

Can visit_struct handle nested structs or arrays?

Accepted Answer

Yes, but you must register each nested struct individually with macros; arrays can be visited if treated as single fields, but element-wise visitation requires custom visitor logic.

Question 4

How to implement generic equality operators using visit_struct?

Accepted Answer

Use binary visitation with a visitor that compares each pair of fields; the README provides an eq_visitor example that short-circuits and compiles to efficient assembly.

Question 5

Is visit_struct compatible with C++17 or C++20?

Accepted Answer

Yes, it works with newer standards, but C++17's structured bindings or C++20 reflection proposals might reduce its utility for some use cases, as noted in the limitations.

Question 6

How to increase the maximum number of visitable members?

Accepted Answer

Edit the library source to raise visit_struct::max_visitable_members or max_visitable_members_intrusive, as documented in IMPLEMENTATION_NOTES.md—this requires recompilation.

Question 7

Does visit_struct support visiting private members?

Accepted Answer

No, it only accesses public members; you'd need to modify the struct definition or use friends, which limits its use in encapsulated codebases.

visit_struct

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