Specs

struct(module() | struct(), Enum.t()) :: struct()

Creates and updates a struct.

The struct argument may be an atom (which defines defstruct) or a struct itself. The second argument is any Enumerable that emits two-element tuples (key-value pairs) during enumeration.

Keys in the Enumerable that don't exist in the struct are automatically discarded. Note that keys must be atoms, as only atoms are allowed when defining a struct. If keys in the Enumerable are duplicated, the last entry will be taken (same behaviour as Map.new/1).

This function is useful for dynamically creating and updating structs, as well as for converting maps to structs; in the latter case, just inserting the appropriate :__struct__ field into the map may not be enough and struct/2 should be used instead.

Examples

defmodule User do
  defstruct name: "john"
end

struct(User)
#=> %User{name: "john"}

opts = [name: "meg"]
user = struct(User, opts)
#=> %User{name: "meg"}

struct(user, unknown: "value")
#=> %User{name: "meg"}

struct(User, %{name: "meg"})
#=> %User{name: "meg"}

# String keys are ignored
struct(User, %{"name" => "meg"})
#=> %User{name: "john"}