1 error[E0277]: the size for values of type `U` cannot be known at compilation time
2 --> $DIR/suggest-where-clause.rs:7:20
4 LL | fn check<T: Iterator, U: ?Sized>() {
5 | - this type parameter needs to be `std::marker::Sized`
6 LL | // suggest a where-clause, if needed
7 LL | mem::size_of::<U>();
8 | ^ doesn't have a size known at compile-time
10 ::: $SRC_DIR/core/src/mem/mod.rs:LL:COL
12 LL | pub const fn size_of<T>() -> usize {
13 | - required by this bound in `std::mem::size_of`
15 error[E0277]: the size for values of type `U` cannot be known at compilation time
16 --> $DIR/suggest-where-clause.rs:10:5
18 LL | fn check<T: Iterator, U: ?Sized>() {
19 | - this type parameter needs to be `std::marker::Sized`
21 LL | mem::size_of::<Misc<U>>();
22 | ^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
24 ::: $SRC_DIR/core/src/mem/mod.rs:LL:COL
26 LL | pub const fn size_of<T>() -> usize {
27 | - required by this bound in `std::mem::size_of`
29 note: required because it appears within the type `Misc<U>`
30 --> $DIR/suggest-where-clause.rs:3:8
32 LL | struct Misc<T:?Sized>(T);
35 error[E0277]: the trait bound `u64: From<T>` is not satisfied
36 --> $DIR/suggest-where-clause.rs:15:5
38 LL | <u64 as From<T>>::from;
39 | ^^^^^^^^^^^^^^^^^^^^^^ the trait `From<T>` is not implemented for `u64`
41 note: required by `from`
42 --> $SRC_DIR/core/src/convert/mod.rs:LL:COL
44 LL | fn from(_: T) -> Self;
45 | ^^^^^^^^^^^^^^^^^^^^^^
46 help: consider introducing a `where` bound, but there might be an alternative better way to express this requirement
48 LL | fn check<T: Iterator, U: ?Sized>() where u64: From<T> {
51 error[E0277]: the trait bound `u64: From<<T as Iterator>::Item>` is not satisfied
52 --> $DIR/suggest-where-clause.rs:18:5
54 LL | <u64 as From<<T as Iterator>::Item>>::from;
55 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `From<<T as Iterator>::Item>` is not implemented for `u64`
57 note: required by `from`
58 --> $SRC_DIR/core/src/convert/mod.rs:LL:COL
60 LL | fn from(_: T) -> Self;
61 | ^^^^^^^^^^^^^^^^^^^^^^
62 help: consider introducing a `where` bound, but there might be an alternative better way to express this requirement
64 LL | fn check<T: Iterator, U: ?Sized>() where u64: From<<T as Iterator>::Item> {
65 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
67 error[E0277]: the trait bound `Misc<_>: From<T>` is not satisfied
68 --> $DIR/suggest-where-clause.rs:23:5
70 LL | <Misc<_> as From<T>>::from;
71 | ^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `From<T>` is not implemented for `Misc<_>`
73 note: required by `from`
74 --> $SRC_DIR/core/src/convert/mod.rs:LL:COL
76 LL | fn from(_: T) -> Self;
77 | ^^^^^^^^^^^^^^^^^^^^^^
79 error[E0277]: the size for values of type `[T]` cannot be known at compilation time
80 --> $DIR/suggest-where-clause.rs:28:20
82 LL | mem::size_of::<[T]>();
83 | ^^^ doesn't have a size known at compile-time
85 ::: $SRC_DIR/core/src/mem/mod.rs:LL:COL
87 LL | pub const fn size_of<T>() -> usize {
88 | - required by this bound in `std::mem::size_of`
90 = help: the trait `Sized` is not implemented for `[T]`
92 error[E0277]: the size for values of type `[&U]` cannot be known at compilation time
93 --> $DIR/suggest-where-clause.rs:31:5
95 LL | mem::size_of::<[&U]>();
96 | ^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
98 ::: $SRC_DIR/core/src/mem/mod.rs:LL:COL
100 LL | pub const fn size_of<T>() -> usize {
101 | - required by this bound in `std::mem::size_of`
103 = help: the trait `Sized` is not implemented for `[&U]`
105 error: aborting due to 7 previous errors
107 For more information about this error, try `rustc --explain E0277`.