Std::experimental::filesystem::path::append, (3) Linux Manual Page

std::experimental::filesystem::path::append, – std::experimental::filesystem::path::append,

Synopsis

path &operator/=(const path &p);
(1)(filesystem TS)

    template <class Source>
    (2)(filesystem TS)

        path &
        operator/=(const Source &source);

template <class Source>
(3)(filesystem TS)

    path &append(const Source &source);

template <class InputIt>
(4)(filesystem TS)

    path &append(InputIt first, InputIt last);

1) First, appends the preferred directory separator to this, except if any of the
following conditions is true:
* the separator would be redundant (*this already ends with a separator)
* *this is empty, or adding it would turn a relative path to an absolute path in
some other way
* p is an empty path.
* p.native() begins with a directory separator.
Then, appends p.native() to the pathname maintained by *this
2,3) Same as (1), but accepts any std::basic_string, null-terminated multicharacter
string, or an input iterator pointing to a null-terminated multicharacter sequence.
4) Same as (1), but accepts any iterator pair that designates a multicharacter
string.

Parameters

p            – pathname to append
         std::basic_string, null-terminated multicharacter string, or an input
source       – iterator pointing to a null-terminated multicharacter sequence, which
         represents a path name (either in portable or in native format)
first, last  – pair of LegacyInputIterators that specify a multicharacter sequence
         that represents a path name

Type requirements

–
InputIt must meet the requirements of LegacyInputIterator.
–
The value type of InputIt must be one of the encoded character types (char, wchar_t,
char16_t and char32_t)

Return value

*this

Exceptions

May throw filesystem_error on underlying OS API errors or std::bad_alloc if memory
allocation fails.

Example

// Run this code

#include <iostream>

#include <experimental/filesystem>

namespace fs = std::experimental::filesystem;

int main()
{
    fs::path p1 = "C:";
    p1 /= "Users"; // does not insert a separator
                   // "C:Users" is a relative path in Windows
                   // adding directory separator would turn it to an absolute path
    std::cout << "\"C:\" / \"Users\" == " << p1 << '\n';
    p1 /= "batman"; // inserts fs::path::preferred_separator, '\' on Windows
    std::cout << "\"C:\" / \"Users\" / \"batman\" == " << p1 << '\n';
}

Possible output:

"C:" / "Users" == "C:Users"
"C:" / "Users" / "batman" == "C:Users\batman"

std::experimental::filesystem::path::append, (3) Linux Manual Page