Runtime Function - iced::application

Authoritative source: ref/doc/iced/fn.application.html.

# Verified signature

pub fn application<State, Message, Theme, Renderer>(
    boot: impl BootFn<State, Message>,
    update: impl UpdateFn<State, Message>,
    view: impl for<'a> ViewFn<'a, State, Message, Theme, Renderer>,
) -> Application<impl Program<State = State, Message = Message, Theme = Theme>>
where
    State: 'static,
    Message: Send + 'static,
    Theme: Base,
    Renderer: Renderer,

# Use this when...

• You need explicit app boot + runtime configuration.
• You want to configure window settings, theme, fonts, subscriptions, or title.
• You are building production-oriented app startup behavior.

# Minimal example

pub fn main() -> iced::Result {
    iced::application(App::new, App::update, App::view).run()
}

# How it works

application returns a builder. You define boot/update/view once, then layer runtime concerns with chainable methods before .run().

# Common patterns

pub fn main() -> iced::Result {
    iced::application(App::new, App::update, App::view)
        .title("Editor")
        .subscription(App::subscription)
        .theme(App::theme)
        .run()
}

# Gotchas / tips

• Keep boot-time state initialization in boot/new, not in view.
• Add subscriptions from builder or app methods to keep lifecycle clear.
• Prefer application over run once startup behavior is non-trivial.

# Example references

• ref/examples/editor/src/main.rs
• ref/examples/layout/src/main.rs
• ref/examples/modal/src/main.rs

# Related

• Runtime API
• Tasks and Subscriptions