Std::filesystem::path::concat,std::filesystem::path::operator+= (3) Linux Manual Page

std::filesystem::path::concat,std::filesystem::path::operator+= – std::filesystem::path::concat,std::filesystem::path::operator+=

Synopsis

path &operator+=(const path &p);
(1)(since C++ 17)

    path &
    operator+=(const string_type &str);
(2)(since C++ 17)

    path &
    operator+=(std::basic_string_view<value_type> str);

path &operator+=(const value_type *ptr);
(3)(since C++ 17)

    path &
    operator+=(value_type x);
(4)(since C++ 17)

    template <class Source>
    (5)(since C++ 17)

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

template <class CharT>
(6)(since C++ 17)

    path &
    operator+=(CharT x);

template <class Source>
(7)(since C++ 17)

    path &concat(const Source &source);

template <class InputIt>
(8)(since C++ 17)

    path &concat(InputIterator first, InputIterator last);
Concatenates the current path and the argument

1-7) Appends path(other).native() to the pathname stored in *this in the native format. This directly manipulates the value of native() and may not be portable between operating systems.

8) Same as return *this += path(first, last)

Parameters

p – path to append
str – string or string view to append
ptr – pointer to the beginning of a null-terminated string to append
x – single character to append
source – std::basic_string, std::basic_string_view, null-terminated multicharacter string, or an input 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)
–
CharT must be one of the encoded character types (char, wchar_t, char16_t and char32_t)

Return value

*this

Exceptions

May throw std::bad_alloc if memory allocation fails.

Notes

Unlike with append() or operator/=, additional directory separators are never introduced.

Example

// Run this code

#include <iostream>

#include <filesystem>

namespace fs = std::filesystem;

int main()
{
    fs::path p1; // empty path
    p1 += "var"; // does not insert a separator
    std::cout << "\"\" + \"var\" == " << p1 << '\n';
    p1 += "lib"; // does not insert a separator
    std::cout << "\"\" + \"var\" + \"lib\" == " << p1 << '\n';
}

Output:

"" + "var" == "var"
"" + "var" + "lib" == "varlib"

std::filesystem::path::concat,std::filesystem::path::operator+= (3) Linux Manual Page