Charted

• Route language: dynamic and static route expressions (A.B[2].C)
• JSON adapter: ergonomic access on top of nlohmann::json
• Two integration styles: header include and C++20 modules
• Single CMake target name: always link charted::charted

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Why Charted

Charted focuses on route-driven data access with clear trade-offs:

• DynamicRoute is ideal when route strings come from runtime inputs.
• StaticRoute enables compile-time parsing and route literal validation.
• Json gives a consistent API for key-based and route-based access.

Static routes are not guaranteed to be faster in all runtime cases, but they are valuable for compile-time correctness.

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Quick Start

Header include style

#include <charted/charted.hpp>
#include <charted_json/charted_json.hpp>

auto dynamic_route = charted::route("A.B[2].C");
auto static_route  = charted::route<"A.B[2].C">();

charted::Json json;
json.Set(dynamic_route, 42);

int value = json.Get<int>(static_route, -1);

C++20 module style

import charted;
import charted.json;

auto dynamic_route = charted::route("A.B[2].C");
auto static_route  = charted::route<"A.B[2].C">();

charted::Json json;
json.Set(dynamic_route, 42);
int value = json.Get<int>(static_route, -1);

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Route API

auto r1 = charted::route("Root.Config.Modules[3].Name");      // dynamic route
auto r2 = charted::route<"Root.Config.Modules[3].Name">();     // static route

Compile-time validation example:

constexpr auto route_ok = charted::route<"Root.Config.Modules[3].Name">();
static_assert(route_ok.IsValid(), "route literal should be valid");

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Json API

charted::Json json;

json.Set("name", "Charted");
json.Set(charted::route("A.B[1].C"), 7);

std::string name = json.Get<std::string>("name", "unknown");
int v = json.Get<int>(charted::route<"A.B[1].C">(), -1);

auto try_v = json.TryGet<int>(charted::route("A.B[1].Missing"));

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Build with CMake

Charted currently does not provide find_package(charted) config files yet. Use one of the following integration methods.

Option 1: add_subdirectory

add_subdirectory(path/to/Charted)
target_link_libraries(your_target PRIVATE charted::charted)

Option 2: FetchContent

include(FetchContent)

FetchContent_Declare(
  charted
  GIT_REPOSITORY https://github.com/LJYC-ME/Charted.git
  GIT_TAG main
)
FetchContent_MakeAvailable(charted)

target_link_libraries(your_target PRIVATE charted::charted)

Project options:

• CHARTED_BUILD_EXAMPLES (default: OFF)
• CHARTED_ENABLE_MODULES (default: OFF, requires CMake >= 3.28)

Mode reminder

• By default, Charted is used as a header-only library.
• Turn CHARTED_ENABLE_MODULES=ON to build and use the C++20 module bindings.
• In both modes, the public CMake target name is still charted::charted.

When modules are enabled, the public link target is still charted::charted.

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Examples

• Runtime/benchmark example: examples/overview.cpp
• Module smoke test: examples/charted_module.cppm, examples/charted_module_main.cpp

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Documentation

Official documentation:

• https://charted.ljyc.me

Local docs source is under documents/ with these sections:

• Overview
• Route
• Json
• Benchmark

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Author

• LJYC (LJYC-ME)