# Pre-RFC: User-provided default field values

**URL:** <https://internals.rust-lang.org/t/pre-rfc-user-provided-default-field-values/15877>\
**Category:** language design\
**Created:** [December 29, 2021, 6:59pm UTC](https://internals.rust-lang.org/t/pre-rfc-user-provided-default-field-values/15877 "2021-12-29T18:59:13Z")\
**Posts on this page:** 1\
**Showing post:** 19

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**Author:** ![scottmcm](https://sea2.discourse-cdn.com/flex002/user_avatar/internals.rust-lang.org/scottmcm/32/2355_2.png) [@scottmcm](https://internals.rust-lang.org/u/scottmcm)\
**Post date:** [December 31, 2021, 6:17pm UTC](https://internals.rust-lang.org/t/pre-rfc-user-provided-default-field-values/15877/19 "2021-12-31T18:17:47Z")

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cc @ekuber , since I'd still like to see exactly what was worked out in their previous thread

> [@Pre-pre-RFC: syntactic sugar for \`Default::default()\`](https://internals.rust-lang.org/t/pre-pre-rfc-syntactic-sugar-for-default-default/13234/75):
>
> Thanks @spacekookie! I know is a long thread so it is a good time to summarize what the RFC I'll be writing will propose, particularly because it is removed from what I originally wrote: Language support for default values on structs through const expressions: struct Car { wheel\_count: usize = 4; } Language support for partially defaulted structs: struct Person { name: String, age: i128 = 0; } Teach #[derive(Default)] to use the default values #[derive(Default)] struct P…

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