error[E0277]: the size for values of type `str` cannot be known at compilation time --> $DIR/dst-rvalue.rs:4:33 | LL | let _x: Box = Box::new(*"hello world"); | -------- ^^^^^^^^^^^^^^ doesn't have a size known at compile-time | | | required by a bound introduced by this call | = help: the trait `Sized` is not implemented for `str` note: required by a bound in `Box::::new` --> $SRC_DIR/alloc/src/boxed.rs:LL:COL error[E0277]: the size for values of type `[isize]` cannot be known at compilation time --> $DIR/dst-rvalue.rs:8:37 | LL | let _x: Box<[isize]> = Box::new(*array); | -------- ^^^^^^ doesn't have a size known at compile-time | | | required by a bound introduced by this call | = help: the trait `Sized` is not implemented for `[isize]` note: required by a bound in `Box::::new` --> $SRC_DIR/alloc/src/boxed.rs:LL:COL error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0277`.