operator<<,>>(std::filesystem::path)

 

C++

Language

Standard Library Headers

Freestanding and hosted implementations

Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

 

Filesystem library

Classes
filesystem::path filesystem::filesystem_error filesystem::directory_entry filesystem::directory_iterator filesystem::recursive_directory_iterator filesystem::file_status	filesystem::space_info filesystem::file_type filesystem::perms filesystem::perm_options filesystem::copy_options filesystem::directory_options filesystem::file_time_type
Functions
filesystem::absolute filesystem::canonicalfilesystem::weakly_canonical filesystem::relativefilesystem::proximate filesystem::copy filesystem::copy_file filesystem::copy_symlink filesystem::create_directory filesystem::create_directories filesystem::create_hard_link filesystem::create_symlink filesystem::create_directory_symlink filesystem::current_path	filesystem::exists filesystem::equivalent filesystem::file_size filesystem::hard_link_count filesystem::last_write_time filesystem::permissions filesystem::read_symlink filesystem::remove filesystem::remove_all filesystem::rename filesystem::resize_file filesystem::space filesystem::status filesystem::symlink_status filesystem::temp_directory_path
File types
filesystem::is_block_file filesystem::is_character_file filesystem::is_directory filesystem::is_empty filesystem::status_known	filesystem::is_fifo filesystem::is_other filesystem::is_regular_file filesystem::is_socket filesystem::is_symlink

 

std::filesystem::path

Constants
path::native_formatpath::generic_formatpath::auto_format
Member functions
path::path path::~path path::operator= path::assign path::appendpath::operator /= path::concatpath::operator += path::clear path::make_preferred path::remove_filename path::replace_filename path::replace_extension path::swap path::compare path::beginpath::end	path::c_strpath::nativepath::operator string_type path::stringpath::u8stringpath::u16stringpath::u32stringpath::wstring path::generic_stringpath::generic_u8stringpath::generic_u16stringpath::generic_u32stringpath::generic_wstring path::lexically_normalpath::lexically_relativepath::lexically_proximate
Path decomposition
path::root_name path::root_directory path::root_path path::relative_path path::parent_path path::filename path::stem path::extension path::empty	path::has_root_pathpath::has_root_namepath::has_root_directorypath::has_relative_pathpath::has_parent_pathpath::has_filenamepath::has_stempath::has_extension path::is_absolutepath::is_relative
Non-member functions
swap(path)
hash_value
operator==operator!=operator<operator<=operator>operator>=
operator/
operator<<operator>>
u8path

 

template< class CharT, class Traits > std::basic_ostream<CharT,Traits>&     operator<<( std::basic_ostream<CharT,Traits>& os, const std::filesystem::path& p );	(1)	(since C++17)
template< class CharT, class Traits > std::basic_istream<CharT,Traits>&     operator>>( std::basic_istream<CharT,Traits>& is, std::filesystem::path& p );	(2)	(since C++17)

Performs stream input or output on the path p. std::quoted is used so that spaces do not cause truncation when later read by stream input operator.

These function templates are not visible to ordinary unqualified or qualified lookup , and can only be found by argument-dependent lookup when std::filesystem::path is an associated class of the arguments. This prevents undesirable conversions in the presence of a using namespace std::filesystem; using-directive.

Parameters

os	-	stream to perform output on
is	-	stream to perform input on
p	-	path to insert or extract

Return value

1) os

2) is

Exceptions

(none)

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR	Applied to	Behavior as published	Correct behavior
LWG 2989	C++17	allowed insertion of everything convertible to path in the presence of a using-directive	made hidden friend

Possible implementation

First version
template< class CharT, class Traits > std::basic_ostream<CharT,Traits>& operator<<( std::basic_ostream<CharT,Traits>& os, const path& p ) { os << std::quoted(p.string<CharT,Traits>()); return os; }
Second version
template< class CharT, class Traits > std::basic_istream<CharT,Traits>& operator>>( std::basic_istream<CharT,Traits>& is, path& p ) { std::basic_string<CharT, Traits> t; is >> std::quoted(t); p = t; return is; }

Example

Run this code

#include <iostream>
#include <filesystem>
int main()
{
	std::cout << std::filesystem::current_path() << '\n';
}

Possible output:

"/home/user"