std::filesystem::directory_entry::is_directory

bool is_directory() const;
 (1) (since C++17) 
bool is_directory( std::error_code& ec ) const noexcept;
 (2) (since C++17)

Checks whether the pointed-to object is a directory. Effectively returns:

1) std::filesystem::is_directory(status()),
2) std::filesystem::is_directory(status(ec)).

Parameters

ec - out-parameter for error reporting in the non-throwing overload

Return value

true if the referred-to filesystem object is a directory, false otherwise.

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 p 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.

Example

#include <filesystem>
#include <iostream>
#include <string_view>
 
namespace fs = std::filesystem;
 
void check_directory(fs::directory_entry const& d, std::string_view rem = "")
{
    std::cout << "is_directory(" << d << "): " << d.is_directory() << rem << '\n';
}
 
int main()
{
    fs::directory_entry d1(".");
    fs::directory_entry d2("file.txt");
    fs::directory_entry d3("new_dir");
 
    std::cout << std::boolalpha;
 
    check_directory(d1);
    check_directory(d2);
    check_directory(d3, " (has not been created yet).");
 
    std::filesystem::create_directory("new_dir");
 
    check_directory(d3, " (before refresh).");
    d3.refresh();
    check_directory(d3, " (after refresh).");
}

Possible output:

is_directory("."): true
is_directory("file.txt"): false
is_directory("new_dir"): false (has not been created yet).
is_directory("new_dir"): false (before refresh).
is_directory("new_dir"): true (after refresh).

See also

(C++17)
 checks whether the given path refers to a directory
(function)

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