Vix.cpp

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Config API ​

This page documents the configuration loader in Vix.

Header:

cpp
#include <vix/config/Config.hpp>

Core type:

cpp
vix::config::Config

The configuration system is:

  • JSON-based
  • Strongly typed
  • Path-addressable via dot notation
  • Safe with fallback defaults

Constructor ​

cpp
vix::config::Config cfg{"config.json"};

Loads and parses the JSON file at construction.

If the file cannot be loaded, behavior depends on implementation configuration. In production, always validate at boot time.

Getters ​

All getters accept:

  • dot path string
  • fallback value

get_string ​

cpp
std::string value = cfg.get_string("server.host", "127.0.0.1");

get_int ​

cpp
int port = cfg.get_int("server.port", 8080);

get_bool ​

cpp
bool debug = cfg.get_bool("runtime.debug", false);

get_double ​

cpp
double ratio = cfg.get_double("limits.ratio", 0.5);

Dot Path Access ​

Nested JSON can be accessed using dot notation.

Given:

json
{
  "database": {
    "host": "localhost",
    "port": 5432
  }
}

Access:

cpp
cfg.get_string("database.host", "127.0.0.1");
cfg.get_int("database.port", 3306);

Minimal Usage Example ​

cpp
#include <vix/config/Config.hpp>
#include <iostream>

int main()
{
  vix::config::Config cfg{"config.json"};

  std::string host = cfg.get_string("server.host", "0.0.0.0");
  int port = cfg.get_int("server.port", 8080);

  std::cout << host << ":" << port << "\n";

  return 0;
}

Environment Override Pattern ​

Configuration files should not contain secrets in production.

Example override:

cpp
#include <vix/config/Config.hpp>
#include <cstdlib>

int main()
{
  vix::config::Config cfg{"config.json"};

  int port = cfg.get_int("server.port", 8080);

  if (const char* env = std::getenv("PORT"))
    port = std::atoi(env);

  return port;
}

Design Notes ​

  • Configuration is read at startup.
  • No global mutable config state.
  • Safe access always requires fallback.
  • Deterministic behavior: no implicit environment merging.

The Config API is intentionally small and predictable.