BoostFilesystem

BoostFilesystem, commonly referred to as Boost.Filesystem, is a library in the Boost C++ Libraries that provides portable facilities for performing common filesystem tasks. It offers cross-platform path handling, directory iteration, and utilities for querying and manipulating files and directories.

Core components include boost::filesystem::path, which stores an abstract representation of a filesystem path and supports convenient lexically based operations through operators such as / and /=. The library exposes a range of functions for common tasks, including exists, is_directory, is_regular_file, create_directory, create_directories, remove, remove_all, copy_file, and rename, as well as facilities for querying and manipulating permissions, timestamps, and space information. Directory iteration is provided by directory_iterator and recursive_directory_iterator for traversing directory trees. Additional utilities cover file_time_type and last_write_time, among others.

Error handling in Boost.Filesystem is supported through exceptions (boost::filesystem::filesystem_error) and non-throwing overloads that take boost::system::error_code, reflecting its integration with Boost.System. The API is designed to be portable across platforms and compilers, and it is commonly used in projects requiring consistent filesystem behavior across environments.

Relation to the standard library: with the advent of C++17, std::filesystem became part of the standard library. Boost.Filesystem maintains a long-standing, compatible API and can be used independently or alongside std::filesystem in configurations that rely on Boost features or broader compiler support. Historically, Boost.Filesystem has undergone major revisions (notably the v3 API) to improve consistency, safety, and integration within the Boost ecosystem. It remains a widely used dependency for cross-platform filesystem functionality in C++ projects.