Minimal modern I/O utilities for C++20.

io provides deterministic filesystem helpers and a contiguous owning byte buffer without hidden behavior.

Header-only by default. Zero external dependencies.

https://github.com/rixcpp/rix

(Part of the Rix modular utility library)

Basic I/O utilities are required in:

• File manipulation
• Temporary file handling
• Binary serialization
• Network payload construction
• Buffer transformations
• System utilities

This module provides:

• Path existence checks
• File size retrieval
• Temporary path generation
• Owning contiguous byte buffer
• Text append helpers
• Binary POD read/write

No implicit encoding. No automatic endian conversion. No hidden state.

Just minimal deterministic I/O tools.

find_package(rix REQUIRED)

Link your target:

target_link_libraries(my_app PRIVATE rix::io)

target_link_libraries(my_app PRIVATE rix::all)

Clone the repository:

git clone https://github.com/rixcpp/rix.git

Add the include/ directory from modules/io to your project.

#include <rix/io/util.hpp>
#include <iostream>

int main()
{
  if (rix::io::path_exists("data.txt"))
  {
    std::cout << "File exists\n";
  }
}

#include <rix/io/util.hpp>
#include <iostream>

int main()
{
  try
  {
    auto size = rix::io::path_size("data.bin");
    std::cout << size << "\n";
  }
  catch (const std::filesystem::filesystem_error& e)
  {
    std::cerr << e.what() << "\n";
  }
}

#include <rix/io/util.hpp>
#include <iostream>

int main()
{
  auto path = rix::io::temp_path("session");
  std::cout << path << "\n";
}

#include <rix/io/buffer.hpp>
#include <iostream>

int main()
{
  rix::io::Buffer buf("hello");

  buf.append(" world");

  std::cout << buf.to_string() << "\n";
}

#include <rix/io/buffer.hpp>
#include <iostream>
#include <cstdint>

int main()
{
  rix::io::Buffer buf;

  std::uint32_t value = 42;
  buf.append_pod(value);

  auto read = buf.read_pod<std::uint32_t>(0);

  std::cout << read << "\n";
}

• Buffer()
• Buffer(size)
• Buffer(string_view)
• Buffer(span<const std::byte>)
• size()
• empty()
• span()
• to_string()
• append(string_view)
• append(span)
• append_pod<T>(value)
• read_pod<T>(offset)
• write_pod<T>(offset, value)

• path_exists(path)
• path_size(path)
• temp_path(prefix = "rix")

• Explicit over implicit
• No automatic encoding
• No hidden conversions
• Deterministic behavior
• Minimal surface area
• Modern C++20 only

This module is intentionally small.

If you need:

• Endian-aware serialization
• Memory-mapped files
• Async file I/O
• Encoding validation
• Buffered stream abstraction

Build those on top.

• Buffer is backed by std::vector<std::byte>
• POD operations use std::memcpy
• No dynamic polymorphism
• No virtual dispatch
• No heap allocations beyond vector growth

Designed for clarity and predictable behavior.

Run:

cmake --preset dev-ninja
cmake --build --preset dev-ninja
ctest --preset dev-ninja

Tests verify:

• Path helpers
• Buffer append correctness
• Binary read/write integrity
• Boundary checks
• Exception behavior

MIT License Copyright (c) Gaspard Kirira