<experimental/filesystem>

Important

This article documents the historical, prestandard MSVC implementation of the File System Technical Specification that was provided in the <experimental/filesystem> header. It's not the C++17 std::filesystem library. This experimental implementation was removed starting in MSVC version 14.51. For current file system support, use the C++17 <filesystem> header and the std::filesystem namespace.

Use this documentation only when maintaining older code that includes <experimental/filesystem> or uses the std::experimental::filesystem namespace. The reference links on this page stay within that historical API unless they're explicitly labeled as current C++17 documentation.

Before C++17 standardized file system support, MSVC shipped a prestandard implementation of the File System Technical Specification in the <experimental/filesystem> header, under the std::experimental::filesystem namespace. This article is retained for historical reference. New code should use the C++17 <filesystem> header instead.

Syntax

#include <experimental/filesystem> // Removed starting in MSVC version 14.51
using namespace std::experimental::filesystem::v1;

Visual Studio version history

• When Visual Studio 2017 was released, the C++17 <filesystem> header wasn't yet standardized. C++ in Visual Studio 2017 implemented the prestandard File System Technical Specification in the <experimental/filesystem> header.
• Visual Studio 2017 version 15.7 and later added support for the new C++17 <filesystem> standard. This C++17 implementation is a completely new implementation, incompatible with the previous std::experimental version.
• In Visual Studio 2019 version 16.3 and later, including <filesystem> provides only the new std::filesystem, and including <experimental/filesystem> provides only the old experimental implementation.
• The experimental implementation was removed starting in MSVC Build Tools version 14.51, which became the default toolset in Visual Studio 2026 version 18.6.

Classes

Name	Description
directory_entry class	Describes an object that is returned by a directory_iterator or a recursive_directory_iterator and contains a path.
directory_iterator class	Describes an input iterator that sequences through the file names in a file-system directory.
filesystem_error class	A base class for exceptions that are thrown to report a low-level system error.
path class	Defines a class that stores an object of template type String that is suitable for use as a file name.
recursive_directory_iterator class	Describes an input iterator that sequences through the file names in a file-system directory. The iterator can also descend into subdirectories.
file_status class	Wraps a file_type.

Structs

Name	Description
space_info structure	Holds information about a volume.

Functions

<experimental/filesystem> functions

Operators

<experimental/filesystem> operators

Enumerations

Name	Description
copy_options	An enumeration that is used with copy_file and determines behavior if a destination file already exists.
directory_options	An enumeration that specifies options for directory iterators.
file_type	An enumeration for file types.
perms	A bitmask type used to convey permissions and options to permissions.

See also

Current <filesystem> documentation