cpp/experimental/fs/is directory

Checks if the given file status or path corresponds to a directory.

@1@ Equivalent to.

@2@ Equivalent to.

@3@ Equivalent to. Returns if error occurs.

Return value
if the given path or file status corresponds to a directory, otherwise.

Exceptions
@1,3@

@2@ Throws if an error occurs. The exception object is constructed with as an argument.