terraform/website/docs/configuration/functions/toset.html.md

layout	page_title	sidebar_current	description
language	toset - Functions - Configuration Language	docs-funcs-conversion-toset	The toset function converts a value to a set.

toset Function

-> Note: This page is about Terraform 0.12 and later. For Terraform 0.11 and earlier, see 0.11 Configuration Language: Interpolation Syntax.

toset converts its argument to a set value.

Explicit type conversions are rarely necessary in Terraform because it will convert types automatically where required. Use the explicit type conversion functions only to normalize types returned in module outputs.

Pass a list value to toset to convert it to a set, which will remove any duplicate elements and discard the ordering of the elements.

Examples

> toset(["a", "b", "c"])
[
  "a",
  "b",
  "c",
]

Since Terraform's concept of a set requires all of the elements to be of the same type, mixed-typed elements will be converted to the most general type:

> toset(["a", "b", 3])
[
  "a",
  "b",
  "3",
]

Set collections are unordered and cannot contain duplicate values, so the ordering of the argument elements is lost and any duplicate values are coalesced:

> toset(["c", "b", "b"])
[
  "b",
  "c",
]