74 lines
1.9 KiB
Markdown
74 lines
1.9 KiB
Markdown
# C++20 Accessors in tomlc17
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The library includes C++ class and routines in the `toml` namespace. These constructs provide:
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- **Safe resource management** - Result class respects RAII rules.
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- **Direct subtable access** – Retrieves values from nested subtables directly.
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- **Safe value access** – Uses C++ `std::optional` for error handling, throwing exceptions on invalid access.
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- **Time and date support** – Represents timestamps as `std::chrono` objects for precise time handling.
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- **Array conversion** – Converts datum arrays into integer or string vectors for easy manipulation.
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## Usage
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Here is a simple example:
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```c++
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/*
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* Parse the config file simple.toml:
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*
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* [server]
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* host = "www.example.com"
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* port = [8080, 8181, 8282]
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*
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*/
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#include "../src/tomlcpp.hpp"
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#include <iostream>
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#include <vector>
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using std::cout;
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static void error(const char *msg) {
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fprintf(stderr, "ERROR: %s\n", msg);
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exit(1);
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}
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int main() {
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// Parse the toml file
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toml::Result result = toml::parse_file_ex("simple.toml");
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// Check for parse error
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if (!result.ok()) {
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error(result.errmsg());
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}
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// Extract values
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std::string host;
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std::vector<int64_t> port;
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try {
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// use the Datum::get() method
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host = result.get({"server", "host"})->as_str().value();
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} catch (const std::bad_optional_access &ex) {
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error("missing or invalid 'server.host' property in config");
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}
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try {
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// use the Datum::seek() method
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port = result.seek("server.port")->as_intvec().value();
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} catch (const std::bad_optional_access &ex) {
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error("missing or invalid 'server.port' property in config");
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}
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// Print values
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cout << "server.host = " << host << "\n";
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cout << "server.port = [";
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for (size_t i = 0; i < port.size(); i++) {
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cout << (i ? ", " : "") << port[i];
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}
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cout << "]\n";
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// Done! No need to call toml_free(). Result::~Result() will handle destruction.
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return 0;
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}
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```
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