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

Returns the directory location suitable for temporary files.



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.


The overload that does not take a std::error_code& parameter throws filesystem_error on underlying OS API errors, constructed with path to be returned as the first argument and the OS error code as the error code argument. std::bad_alloc may be thrown if memory allocation fails. The overload taking a std::error_code& parameter sets it to the OS API error code if an OS API call fails, and executes ec.clear() if no errors occur. This overload has
noexcept specification:  


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


#include <iostream>
#include <filesystem>
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