Implement C++ library with C API for JSON/TOML parsing using Boost.Json and Toml++

[Copilot]

Creates a specification format library with dual JSON/TOML support, exposing a clean C API while using modern C++17 internally.

Architecture

C API Layer (include/ryspec/ryspec.h)

• Opaque types (ryspec_context_t, ryspec_document_t) hide implementation
• Result codes for error handling
• String, int64, and bool value accessors

Internal C++ Layer (src/ryspec/)

• std::variant<boost::json::value, toml::table> for unified document representation
• Template-based type extraction with format-specific specializations
• RAII resource management wrapped by C create/destroy functions

Build System

• CMake with find_package for Boost, FetchContent for Toml++
• Shared library, demo app, and test suite

Usage

ryspec_context_t* ctx = ryspec_context_create();

ryspec_document_t* doc;
ryspec_parse_string(ctx, "{\"name\":\"example\"}", RYSPEC_FORMAT_JSON, &doc);

char name[256];
ryspec_get_string(doc, "name", name, sizeof(name));

ryspec_document_destroy(doc);
ryspec_context_destroy(ctx);

TOML parsing identical except RYSPEC_FORMAT_TOML. File parsing via ryspec_parse_file().

Implementation Notes

• Error messages valid until next context operation (standard C pattern)
• String buffer requires null termination handling
• Both string and file parsing supported for each format

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• esm.ubuntu.com
  • Triggering command: /usr/lib/apt/methods/https /usr/lib/apt/methods/https (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

Prepare a C++ and library and application using Boost.Json and Toml++ libraries, built by cmake. The library must have a C API and internal types hiding internal implementation.

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