Make `dyn` inlay hints configurable

[lnicola]

Discussed in #21052

^{Originally posted by matthew-mcallister November 18, 2025}
In the VS Code extension, is there any way to disable the lens that displays the "dyn" keyword in locations where it is implicit? I can't seem to find any configuration variable that affects this.

[lnicola]

We need to add a new field to

rust-analyzer/crates/ide/src/inlay_hints.rs

Line 303 in afcfe14

pub struct InlayHintsConfig<'a> {

, check it at the start of

rust-analyzer/crates/ide/src/inlay_hints/implied_dyn_trait.rs

Line 11 in afcfe14

pub(super) fn hints(

(cf.

rust-analyzer/crates/ide/src/inlay_hints/implicit_static.rs

Line 21 in afcfe14

if config.lifetime_elision_hints != LifetimeElisionHints::Always {

), then wire it up in

rust-analyzer/crates/rust-analyzer/src/config.rs

Line 1905 in afcfe14

pub fn inlay_hints<'a>(&self, minicore: MiniCore<'a>) -> InlayHintsConfig<'a> {

.