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

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

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

Possible output:

"/home/user"

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