Pros of yyjson

• Focuses on JSON parsing and serialization, offering high performance
• Provides both mutable and immutable APIs for flexibility
• Supports JSON pointer for easy data access and modification

Cons of yyjson

• Limited to JSON-related functionality
• Lacks date and time manipulation features
• May require additional libraries for non-JSON operations

Code Comparison

date:

#include "date/date.h"
using namespace date;
auto d = 2015_y/March/22;
auto t = make_time(13, 30, 0);
auto dt = d + t;

yyjson:

yyjson_doc *doc = yyjson_read(json, len, 0);
yyjson_val *root = yyjson_doc_get_root(doc);
const char *name = yyjson_get_str(yyjson_obj_get(root, "name"));
yyjson_doc_free(doc);

Key Differences

• date focuses on date and time manipulation, while yyjson specializes in JSON processing
• date is a C++ library, whereas yyjson is written in C
• yyjson offers more JSON-specific features, while date provides comprehensive date/time utilities
• date is part of the C++ standard proposal, potentially becoming a built-in feature in future C++ versions

Pros of fmt

• Broader scope: fmt is a general-purpose formatting library, while date focuses specifically on date and time handling
• More active development: fmt has more recent commits and a larger community of contributors
• Extensive formatting options: Supports a wide range of formatting styles for various data types

Cons of fmt

• Larger library size: fmt covers more functionality, potentially increasing binary size
• Steeper learning curve: More features may require more time to master compared to date's focused approach
• Not specialized for date/time: May lack some specific date and time manipulation features found in date

Code Comparison

date:

#include "date/date.h"
auto d = date::year{2023}/date::month{3}/date::day{14};
std::cout << d << '\n';

fmt:

#include <fmt/chrono.h>
auto d = std::chrono::year{2023}/std::chrono::month{3}/std::chrono::day{14};
fmt::print("{:%Y-%m-%d}\n", d);

Both libraries provide ways to work with dates, but fmt offers a more flexible formatting approach while date provides more specialized date/time functionality.

Pros of json

• Wider scope: Handles JSON parsing, serialization, and manipulation
• More extensive documentation and examples
• Larger community and more frequent updates

Cons of json

• Larger library size and potential performance overhead
• Less specialized, may not be as optimized for specific use cases

Code Comparison

date:

#include "date/date.h"
auto d = date::year{2023}/4/1;
std::cout << d << '\n';

json:

#include <nlohmann/json.hpp>
nlohmann::json j = {{"name", "John"}, {"age", 30}};
std::cout << j.dump(4) << '\n';

Key Differences

• Scope: date focuses on date and time handling, while json is for JSON data
• Usage: date is primarily for temporal calculations, json for data serialization
• Integration: json may be easier to integrate into projects dealing with web APIs or data exchange

Conclusion

Both libraries serve different purposes. date is specialized for date and time operations, while json offers a comprehensive solution for working with JSON data. The choice between them depends on the specific requirements of your project.

Pros of spdlog

• Broader functionality: spdlog is a comprehensive logging library, while date focuses solely on date and time handling
• Performance-oriented: spdlog is designed for high-performance logging with minimal overhead
• Thread-safe: spdlog supports concurrent logging from multiple threads

Cons of spdlog

• Larger codebase: spdlog has a more extensive codebase, which may increase compilation times
• Steeper learning curve: spdlog's wider range of features may require more time to master

Code Comparison

spdlog example:

#include "spdlog/spdlog.h"

int main() {
    spdlog::info("Welcome to spdlog!");
    spdlog::error("An error message with format: {}", 42);
}

date example:

#include "date/date.h"
#include <iostream>

int main() {
    auto today = date::year_month_day{date::floor<date::days>(std::chrono::system_clock::now())};
    std::cout << "Today is " << today << '\n';
}

While both libraries serve different purposes, they demonstrate clean and intuitive APIs for their respective domains. spdlog provides a straightforward logging interface, while date simplifies date and time operations in modern C++.

Pros of rapidjson

• Focuses on JSON parsing and serialization, offering more specialized features for JSON handling
• Generally faster performance for JSON operations
• Supports in-situ parsing, reducing memory allocation

Cons of rapidjson

• Limited to JSON-related functionality
• Larger codebase and potentially more complex API
• May require more setup and configuration for basic usage

Code Comparison

date:

#include "date/date.h"
auto d = date::year{2023}/4/1;

rapidjson:

#include "rapidjson/document.h"
rapidjson::Document d;
d.Parse("{\"date\":\"2023-04-01\"}");

Key Differences

• date focuses on date and time manipulation, while rapidjson specializes in JSON handling
• date provides a more intuitive API for working with dates, while rapidjson offers powerful JSON parsing capabilities
• date is header-only and easier to integrate, while rapidjson may require more setup but offers more JSON-specific features

Use Cases

• Choose date for projects primarily dealing with date and time calculations
• Opt for rapidjson when working extensively with JSON data or requiring high-performance JSON parsing

Community and Support

• Both projects have active communities and are well-maintained
• date has fewer contributors but is widely used in the C++ community
• rapidjson has a larger contributor base and is backed by Tencent

Pros of double-conversion

• Focused on efficient and accurate conversion between binary and decimal floating-point numbers
• Extensively tested and optimized for performance
• Widely used in various projects, including V8 JavaScript engine

Cons of double-conversion

• Limited scope, only handles floating-point conversions
• Less comprehensive date and time functionality
• Requires more manual integration for complex date/time operations

Code Comparison

date:

#include "date/date.h"
using namespace date;
auto d = 2023_y/3/14;
auto t = make_time(12, 30, 0);
auto dt = sys_days{d} + t;

double-conversion:

#include "double-conversion/double-conversion.h"
double_conversion::DoubleToStringConverter converter(flags, infinity_symbol, nan_symbol, exponent_character, decimal_in_shortest_low, decimal_in_shortest_high, max_leading_padding_zeroes_in_precision_mode, max_trailing_padding_zeroes_in_precision_mode);
char buffer[128];
double_conversion::StringBuilder builder(buffer, sizeof(buffer));
converter.ToShortest(3.14159, &builder);

Summary

date provides comprehensive date and time functionality, while double-conversion focuses on efficient floating-point conversions. date offers easier-to-use APIs for date/time operations, whereas double-conversion requires more setup but excels in its specific domain. Choose based on your project's primary needs: date/time manipulation or precise floating-point conversions.