std::filesystem:: temp_directory_path

From cppreference.com
Defined in header <filesystem>
path temp_directory_path ( ) ;
(1) (since C++17)
path temp_directory_path ( std:: error_code & ec ) ;
(2) (since C++17)

Returns the directory location suitable for temporary files.

Parameters

(none)

Return value

A directory suitable for temporary files. The path is guaranteed to exist and to be a directory. The overload that takes error_code & argument returns an empty path on error.

Exceptions

Any overload not marked noexcept may throw std::bad_alloc if memory allocation fails.

1) Throws std::filesystem::filesystem_error on underlying OS API errors, constructed with path to be returned as the first path argument and the OS error code as the error code argument.
2) Sets a std:: error_code & parameter to the OS API error code if an OS API call fails, and executes ec. clear ( ) if no errors occur.

Notes

On POSIX systems, the path may be the one specified in the environment variables TMPDIR , TMP , TEMP , TEMPDIR , and, if none of them are specified, the path "/tmp" is returned.

On Windows systems, the path is typically the one returned by GetTempPath .

Example

#include <filesystem>
#include <iostream>
namespace fs = std::filesystem;
 
int main()
{
    std::cout << "Temp directory is " << fs::temp_directory_path() << '\n';
}

Possible output:

Temp directory is "C:\Windows\TEMP\"

See also

creates and opens a temporary, auto-removing file
(function)
returns or sets the current working directory
(function)