# std::filesystem::is_empty

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< cpp‎ | filesystem

Defined in header `<filesystem>` |  |
bool is_empty( const std::filesystem::path& p ); bool is_empty( const std::filesystem::path& p, std::error_code& ec ); |  | (since C++17)

Checks whether the given path refers to an empty file or directory.

### Parameters

p | - | path to examine
ec | - | error code to modify in case of error

### Return value

true if the path indicated by `p` refers to an empty file or directory, false otherwise. The non-throwing overload returns false if an error occurs.

### Exceptions

The overload that does not take a std::error_code& parameter throws `filesystem::filesystem_error` on underlying OS API errors, constructed with `p` as the first path argument and the OS error code as the error code argument. 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. Any overload not marked `noexcept` may throw std::bad_alloc if memory allocation fails.

### Example

Run this code

    #include <filesystem>
    #include <fstream>
    #include <iostream>
    #include <cstdio>

    int main()
    {
        namespace fs = std::filesystem;

        const fs::path tmp_dir{ fs::temp_directory_path() };
        std::cout << std::boolalpha
                  << "Temp dir: " << tmp_dir << '\n'
                  << "is_empty(): " << fs::is_empty(tmp_dir) << '\n';

        const fs::path tmp_name{ tmp_dir / std::tmpnam(nullptr) };
        std::cout << "Temp file: " << tmp_name << '\n';

        std::ofstream file{ tmp_name.string() };
        std::cout << "is_empty(): " << fs::is_empty(tmp_name) << '\n';
        file << "cppreference.com";
        file.flush();
        std::cout << "is_empty(): " << fs::is_empty(tmp_name) << '\n'
                  << "file_size(): " << fs::file_size(tmp_name) << '\n';
        file.close();
        fs::remove(tmp_name);
    }

Possible output:

    Temp dir: "/tmp"
    is_empty(): false
    Temp file: "/tmp/fileCqd9DM"
    is_empty(): true
    is_empty(): false
    file_size(): 16

### Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR | Applied to | Behavior as published | Correct behavior
--- | --- | --- | ---
LWG 3013 | C++17 | `error_code` overload marked noexcept but can allocate memory | noexcept removed

### See also

status symlink_status (C++17)(C++17) | determines file attributes determines file attributes, checking the symlink target (function)
exists (C++17) | checks whether path refers to existing file system object (function)

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