30 Input/output library [input.output]

30.11 File systems [filesystems]

30.11.7 Class path [fs.class.path]

30.11.7.4 path members [fs.path.member]

30.11.7.4.4 path concatenation [fs.path.concat]

path& operator+=(const path& x); path& operator+=(const string_type& x); path& operator+=(basic_string_view<value_type> x); path& operator+=(const value_type* x); path& operator+=(value_type x); template<class Source> path& operator+=(const Source& x); template<class EcharT> path& operator+=(EcharT x); template<class Source> path& concat(const Source& x);
Effects: Appends path(x).native() to the pathname in the native format.
[Note
:
This directly manipulates the value of native() and may not be portable between operating systems.
end note
]
Returns: *this.
template<class InputIterator> path& concat(InputIterator first, InputIterator last);
Effects: Equivalent to: return *this += path(first, last);