error[E0433]: failed to resolve: use of undeclared type `TryFrom` --> $DIR/suggest-tryinto-edition-change.rs:11:19 | LL | let _i: i16 = TryFrom::try_from(0_i32).unwrap(); | ^^^^^^^ use of undeclared type `TryFrom` | = note: 'core::convert::TryFrom' is included in the prelude starting in Edition 2021 = note: 'std::convert::TryFrom' is included in the prelude starting in Edition 2021 help: consider importing one of these items | LL + use core::convert::TryFrom; | LL + use std::convert::TryFrom; | error[E0433]: failed to resolve: use of undeclared type `TryInto` --> $DIR/suggest-tryinto-edition-change.rs:17:19 | LL | let _i: i16 = TryInto::try_into(0_i32).unwrap(); | ^^^^^^^ use of undeclared type `TryInto` | = note: 'core::convert::TryInto' is included in the prelude starting in Edition 2021 = note: 'std::convert::TryInto' is included in the prelude starting in Edition 2021 help: consider importing one of these items | LL + use core::convert::TryInto; | LL + use std::convert::TryInto; | error[E0433]: failed to resolve: use of undeclared type `FromIterator` --> $DIR/suggest-tryinto-edition-change.rs:23:22 | LL | let _v: Vec<_> = FromIterator::from_iter(&[1]); | ^^^^^^^^^^^^ use of undeclared type `FromIterator` | = note: 'core::iter::FromIterator' is included in the prelude starting in Edition 2021 = note: 'std::iter::FromIterator' is included in the prelude starting in Edition 2021 help: a trait with a similar name exists | LL | let _v: Vec<_> = IntoIterator::from_iter(&[1]); | ~~~~~~~~~~~~ help: consider importing one of these items | LL + use core::iter::FromIterator; | LL + use std::iter::FromIterator; | error[E0599]: no method named `try_into` found for type `i32` in the current scope --> $DIR/suggest-tryinto-edition-change.rs:6:25 | LL | let _i: i16 = 0_i32.try_into().unwrap(); | ^^^^^^^^ method not found in `i32` --> $SRC_DIR/core/src/convert/mod.rs:LL:COL | = note: the method is available for `i32` here | = help: items from traits can only be used if the trait is in scope = note: 'std::convert::TryInto' is included in the prelude starting in Edition 2021 help: the following trait is implemented but not in scope; perhaps add a `use` for it: | LL + use std::convert::TryInto; | error: aborting due to 4 previous errors Some errors have detailed explanations: E0433, E0599. For more information about an error, try `rustc --explain E0433`.