error[E0277]: the size for values of type `T` cannot be known at compilation time --> $DIR/unsized-struct.rs:6:36 | LL | fn foo2() { not_sized::>() } | - ^^^^^^ doesn't have a size known at compile-time | | | this type parameter needs to be `std::marker::Sized` | note: required by a bound in `Foo` --> $DIR/unsized-struct.rs:4:12 | LL | struct Foo { data: T } | ^ required by this bound in `Foo` help: you could relax the implicit `Sized` bound on `T` if it were used through indirection like `&T` or `Box` --> $DIR/unsized-struct.rs:4:12 | LL | struct Foo { data: T } | ^ - ...if indirection were used here: `Box` | | | this could be changed to `T: ?Sized`... help: consider removing the `?Sized` bound to make the type parameter `Sized` | LL - fn foo2() { not_sized::>() } LL + fn foo2() { not_sized::>() } | error[E0277]: the size for values of type `T` cannot be known at compilation time --> $DIR/unsized-struct.rs:13:24 | LL | fn bar2() { is_sized::>() } | - ^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time | | | this type parameter needs to be `std::marker::Sized` | note: required because it appears within the type `Bar` --> $DIR/unsized-struct.rs:11:8 | LL | struct Bar { data: T } | ^^^ note: required by a bound in `is_sized` --> $DIR/unsized-struct.rs:1:13 | LL | fn is_sized() { } | ^ required by this bound in `is_sized` help: consider removing the `?Sized` bound to make the type parameter `Sized` | LL - fn bar2() { is_sized::>() } LL + fn bar2() { is_sized::>() } | error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0277`.