# Module :: former_types [](https://github.com/emersion/stability-badges#experimental) [](https://github.com/Wandalen/wTools/actions/workflows/module_former_types_push.yml) [](https://docs.rs/former_types) [](https://gitpod.io/#RUN_PATH=.,SAMPLE_FILE=module%2Fcore%2Fformer_types%2Fexamples%2Fformer_types_trivial.rs,RUN_POSTFIX=--example%20former_types_trivial/https://github.com/Wandalen/wTools) [](https://discord.gg/m3YfbXpUUY) A flexible implementation of the Builder pattern supporting nested builders and collection-specific subformers. Its compile-time structures and traits that are not generated but reused. ## Example: Using Trait Assign Demonstrates setting various components (fields) of a struct. The `former_types` crate provides a generic interface for setting components on an object. This example defines a `Person` struct and implements the `Assign` trait for its fields. It shows how to use these implementations to set the fields of a `Person` instance using different types that can be converted into the required types. ```rust #[ cfg( any( not( feature = "types_former" ), not( feature = "enabled" ) ) ) ] fn main() {} #[ cfg( all( feature = "types_former", feature = "enabled" ) ) ] fn main() { use former_types::Assign; #[ derive( Default, PartialEq, Debug ) ] struct Person { age : i32, name : String, } impl< IntoT > Assign< i32, IntoT > for Person where IntoT : Into< i32 >, { fn assign( &mut self, component : IntoT ) { self.age = component.into(); } } impl< IntoT > Assign< String, IntoT > for Person where IntoT : Into< String >, { fn assign( &mut self, component : IntoT ) { self.name = component.into(); } } let mut got : Person = Default::default(); got.assign( 13 ); got.assign( "John" ); assert_eq!( got, Person { age : 13, name : "John".to_string() } ); dbg!( got ); // > Person { // > age: 13, // > name: "John", // > } } ``` Try out `cargo run --example former_types_trivial`.
[See code](./examples/former_types_trivial.rs).