std::filesystem::filesystem_error::operator=

From cppreference.com
filesystem_error& operator= ( const filesystem_error& other ) noexcept ;
(since C++17)

Assigns the contents with those of other. If *this and other both have dynamic type std::filesystem::filesystem_error then std::strcmp (what( ), other.what ( ) ) == 0

Parameters

other - another filesystem_error object to assign with

Return value

*this

Notes

Typical implementations store path objects referenced by path1() and path2() in a reference-counted storage. As a result, *this and other usually share their path

Example