Kernel.is_struct

You're seeing just the macro is_struct, go back to Kernel module for more information.

is_struct(term)

(macro) (since 1.10.0)

Returns true if term is a struct; otherwise returns false.

Allowed in guard tests.

iex> is_struct(URI.parse("/"))
true

iex> is_struct(%{})
false

(macro) (since 1.11.0)

Returns true if term is a struct of name; otherwise returns false.

Allowed in guard tests.

iex> is_struct(URI.parse("/"), URI)
true

iex> is_struct(URI.parse("/"), Macro.Env)
false