safe transmute: use `Assume` struct to provide analysis options

This was left as a TODO in #92268, and brings the trait more in
line with what was defined in MCP411.

`Assume::visibility` has been renamed to `Assume::safety`, as
library safety is what's actually being assumed; visibility is
just the mechanism by which it is currently checked (this may
change).

ref: https://github.com/rust-lang/compiler-team/issues/411
ref: https://github.com/rust-lang/rust/issues/99571

5 files changed, 202 insertions, 92 deletions

diff --git a/src/test/ui/transmutability/structs/repr/should_handle_align.rs b/src/test/ui/transmutability/structs/repr/should_handle_align.rs
index 71720165ab0..ea9bf2a237e 100644
--- a/src/test/ui/transmutability/structs/repr/should_handle_align.rs
+++ b/src/test/ui/transmutability/structs/repr/should_handle_align.rs
@@ -6,12 +6,19 @@
 #![allow(dead_code, incomplete_features, non_camel_case_types)]
 
 mod assert {
-    use std::mem::BikeshedIntrinsicFrom;
+    use std::mem::{Assume, BikeshedIntrinsicFrom};
     pub struct Context;
 
     pub fn is_maybe_transmutable<Src, Dst>()
     where
-        Dst: BikeshedIntrinsicFrom<Src, Context, true, true, true, true>
+        Dst: BikeshedIntrinsicFrom<Src, Context, {
+            Assume {
+                alignment: true,
+                lifetimes: true,
+                safety: true,
+                validity: true,
+            }
+        }>
     {}
 }
 
diff --git a/src/test/ui/transmutability/structs/repr/should_handle_packed.rs b/src/test/ui/transmutability/structs/repr/should_handle_packed.rs
index ae8acf50418..17dc995fcd9 100644
--- a/src/test/ui/transmutability/structs/repr/should_handle_packed.rs
+++ b/src/test/ui/transmutability/structs/repr/should_handle_packed.rs
@@ -6,12 +6,19 @@
 #![allow(dead_code, incomplete_features, non_camel_case_types)]
 
 mod assert {
-    use std::mem::BikeshedIntrinsicFrom;
+    use std::mem::{Assume, BikeshedIntrinsicFrom};
     pub struct Context;
 
     pub fn is_maybe_transmutable<Src, Dst>()
     where
-        Dst: BikeshedIntrinsicFrom<Src, Context, true, true, true, true>
+        Dst: BikeshedIntrinsicFrom<Src, Context, {
+            Assume {
+                alignment: true,
+                lifetimes: true,
+                safety: true,
+                validity: true,
+            }
+        }>
     {}
 }
 
diff --git a/src/test/ui/transmutability/structs/repr/should_require_well_defined_layout.rs b/src/test/ui/transmutability/structs/repr/should_require_well_defined_layout.rs
index 556be989dbc..9a65b4d702d 100644
--- a/src/test/ui/transmutability/structs/repr/should_require_well_defined_layout.rs
+++ b/src/test/ui/transmutability/structs/repr/should_require_well_defined_layout.rs
@@ -5,12 +5,19 @@
 #![allow(dead_code, incomplete_features, non_camel_case_types)]
 
 mod assert {
-    use std::mem::BikeshedIntrinsicFrom;
+    use std::mem::{Assume, BikeshedIntrinsicFrom};
     pub struct Context;
 
     pub fn is_maybe_transmutable<Src, Dst>()
     where
-        Dst: BikeshedIntrinsicFrom<Src, Context, true, true, true, true>
+        Dst: BikeshedIntrinsicFrom<Src, Context, {
+            Assume {
+                alignment: true,
+                lifetimes: true,
+                safety: true,
+                validity: true,
+            }
+        }>
     {}
 }
 
diff --git a/src/test/ui/transmutability/structs/repr/should_require_well_defined_layout.stderr b/src/test/ui/transmutability/structs/repr/should_require_well_defined_layout.stderr
index 07355f7c2ad..621dbee849f 100644
--- a/src/test/ui/transmutability/structs/repr/should_require_well_defined_layout.stderr
+++ b/src/test/ui/transmutability/structs/repr/should_require_well_defined_layout.stderr
@@ -1,194 +1,278 @@
 error[E0277]: `should_reject_repr_rust::unit::repr_rust` cannot be safely transmuted into `()` in the defining scope of `assert::Context`.
-  --> $DIR/should_require_well_defined_layout.rs:21:52
+  --> $DIR/should_require_well_defined_layout.rs:28:52
    |
 LL |         assert::is_maybe_transmutable::<repr_rust, ()>();
    |                                                    ^^ `should_reject_repr_rust::unit::repr_rust` cannot be safely transmuted into `()` in the defining scope of `assert::Context`.
    |
-   = help: the trait `BikeshedIntrinsicFrom<should_reject_repr_rust::unit::repr_rust, assert::Context, true, true, true, true>` is not implemented for `()`
+   = help: the trait `BikeshedIntrinsicFrom<should_reject_repr_rust::unit::repr_rust, assert::Context, Assume { alignment: true, lifetimes: true, safety: true, validity: true }>` is not implemented for `()`
 note: required by a bound in `is_maybe_transmutable`
   --> $DIR/should_require_well_defined_layout.rs:13:14
    |
-LL |     pub fn is_maybe_transmutable<Src, Dst>()
-   |            --------------------- required by a bound in this
-LL |     where
-LL |         Dst: BikeshedIntrinsicFrom<Src, Context, true, true, true, true>
-   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `is_maybe_transmutable`
+LL |       pub fn is_maybe_transmutable<Src, Dst>()
+   |              --------------------- required by a bound in this
+LL |       where
+LL |           Dst: BikeshedIntrinsicFrom<Src, Context, {
+   |  ______________^
+LL | |             Assume {
+LL | |                 alignment: true,
+LL | |                 lifetimes: true,
+...  |
+LL | |             }
+LL | |         }>
+   | |__________^ required by this bound in `is_maybe_transmutable`
 
 error[E0277]: `u128` cannot be safely transmuted into `should_reject_repr_rust::unit::repr_rust` in the defining scope of `assert::Context`.
-  --> $DIR/should_require_well_defined_layout.rs:22:47
+  --> $DIR/should_require_well_defined_layout.rs:29:47
    |
 LL |         assert::is_maybe_transmutable::<u128, repr_rust>();
    |                                               ^^^^^^^^^ `u128` cannot be safely transmuted into `should_reject_repr_rust::unit::repr_rust` in the defining scope of `assert::Context`.
    |
-   = help: the trait `BikeshedIntrinsicFrom<u128, assert::Context, true, true, true, true>` is not implemented for `should_reject_repr_rust::unit::repr_rust`
+   = help: the trait `BikeshedIntrinsicFrom<u128, assert::Context, Assume { alignment: true, lifetimes: true, safety: true, validity: true }>` is not implemented for `should_reject_repr_rust::unit::repr_rust`
 note: required by a bound in `is_maybe_transmutable`
   --> $DIR/should_require_well_defined_layout.rs:13:14
    |
-LL |     pub fn is_maybe_transmutable<Src, Dst>()
-   |            --------------------- required by a bound in this
-LL |     where
-LL |         Dst: BikeshedIntrinsicFrom<Src, Context, true, true, true, true>
-   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `is_maybe_transmutable`
+LL |       pub fn is_maybe_transmutable<Src, Dst>()
+   |              --------------------- required by a bound in this
+LL |       where
+LL |           Dst: BikeshedIntrinsicFrom<Src, Context, {
+   |  ______________^
+LL | |             Assume {
+LL | |                 alignment: true,
+LL | |                 lifetimes: true,
+...  |
+LL | |             }
+LL | |         }>
+   | |__________^ required by this bound in `is_maybe_transmutable`
 
 error[E0277]: `should_reject_repr_rust::tuple::repr_rust` cannot be safely transmuted into `()` in the defining scope of `assert::Context`.
-  --> $DIR/should_require_well_defined_layout.rs:27:52
+  --> $DIR/should_require_well_defined_layout.rs:34:52
    |
 LL |         assert::is_maybe_transmutable::<repr_rust, ()>();
    |                                                    ^^ `should_reject_repr_rust::tuple::repr_rust` cannot be safely transmuted into `()` in the defining scope of `assert::Context`.
    |
-   = help: the trait `BikeshedIntrinsicFrom<should_reject_repr_rust::tuple::repr_rust, assert::Context, true, true, true, true>` is not implemented for `()`
+   = help: the trait `BikeshedIntrinsicFrom<should_reject_repr_rust::tuple::repr_rust, assert::Context, Assume { alignment: true, lifetimes: true, safety: true, validity: true }>` is not implemented for `()`
 note: required by a bound in `is_maybe_transmutable`
   --> $DIR/should_require_well_defined_layout.rs:13:14
    |
-LL |     pub fn is_maybe_transmutable<Src, Dst>()
-   |            --------------------- required by a bound in this
-LL |     where
-LL |         Dst: BikeshedIntrinsicFrom<Src, Context, true, true, true, true>
-   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `is_maybe_transmutable`
+LL |       pub fn is_maybe_transmutable<Src, Dst>()
+   |              --------------------- required by a bound in this
+LL |       where
+LL |           Dst: BikeshedIntrinsicFrom<Src, Context, {
+   |  ______________^
+LL | |             Assume {
+LL | |                 alignment: true,
+LL | |                 lifetimes: true,
+...  |
+LL | |             }
+LL | |         }>
+   | |__________^ required by this bound in `is_maybe_transmutable`
 
 error[E0277]: `u128` cannot be safely transmuted into `should_reject_repr_rust::tuple::repr_rust` in the defining scope of `assert::Context`.
-  --> $DIR/should_require_well_defined_layout.rs:28:47
+  --> $DIR/should_require_well_defined_layout.rs:35:47
    |
 LL |         assert::is_maybe_transmutable::<u128, repr_rust>();
    |                                               ^^^^^^^^^ `u128` cannot be safely transmuted into `should_reject_repr_rust::tuple::repr_rust` in the defining scope of `assert::Context`.
    |
-   = help: the trait `BikeshedIntrinsicFrom<u128, assert::Context, true, true, true, true>` is not implemented for `should_reject_repr_rust::tuple::repr_rust`
+   = help: the trait `BikeshedIntrinsicFrom<u128, assert::Context, Assume { alignment: true, lifetimes: true, safety: true, validity: true }>` is not implemented for `should_reject_repr_rust::tuple::repr_rust`
 note: required by a bound in `is_maybe_transmutable`
   --> $DIR/should_require_well_defined_layout.rs:13:14
    |
-LL |     pub fn is_maybe_transmutable<Src, Dst>()
-   |            --------------------- required by a bound in this
-LL |     where
-LL |         Dst: BikeshedIntrinsicFrom<Src, Context, true, true, true, true>
-   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `is_maybe_transmutable`
+LL |       pub fn is_maybe_transmutable<Src, Dst>()
+   |              --------------------- required by a bound in this
+LL |       where
+LL |           Dst: BikeshedIntrinsicFrom<Src, Context, {
+   |  ______________^
+LL | |             Assume {
+LL | |                 alignment: true,
+LL | |                 lifetimes: true,
+...  |
+LL | |             }
+LL | |         }>
+   | |__________^ required by this bound in `is_maybe_transmutable`
 
 error[E0277]: `should_reject_repr_rust::braces::repr_rust` cannot be safely transmuted into `()` in the defining scope of `assert::Context`.
-  --> $DIR/should_require_well_defined_layout.rs:33:52
+  --> $DIR/should_require_well_defined_layout.rs:40:52
    |
 LL |         assert::is_maybe_transmutable::<repr_rust, ()>();
    |                                                    ^^ `should_reject_repr_rust::braces::repr_rust` cannot be safely transmuted into `()` in the defining scope of `assert::Context`.
    |
-   = help: the trait `BikeshedIntrinsicFrom<should_reject_repr_rust::braces::repr_rust, assert::Context, true, true, true, true>` is not implemented for `()`
+   = help: the trait `BikeshedIntrinsicFrom<should_reject_repr_rust::braces::repr_rust, assert::Context, Assume { alignment: true, lifetimes: true, safety: true, validity: true }>` is not implemented for `()`
 note: required by a bound in `is_maybe_transmutable`
   --> $DIR/should_require_well_defined_layout.rs:13:14
    |
-LL |     pub fn is_maybe_transmutable<Src, Dst>()
-   |            --------------------- required by a bound in this
-LL |     where
-LL |         Dst: BikeshedIntrinsicFrom<Src, Context, true, true, true, true>
-   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `is_maybe_transmutable`
+LL |       pub fn is_maybe_transmutable<Src, Dst>()
+   |              --------------------- required by a bound in this
+LL |       where
+LL |           Dst: BikeshedIntrinsicFrom<Src, Context, {
+   |  ______________^
+LL | |             Assume {
+LL | |                 alignment: true,
+LL | |                 lifetimes: true,
+...  |
+LL | |             }
+LL | |         }>
+   | |__________^ required by this bound in `is_maybe_transmutable`
 
 error[E0277]: `u128` cannot be safely transmuted into `should_reject_repr_rust::braces::repr_rust` in the defining scope of `assert::Context`.
-  --> $DIR/should_require_well_defined_layout.rs:34:47
+  --> $DIR/should_require_well_defined_layout.rs:41:47
    |
 LL |         assert::is_maybe_transmutable::<u128, repr_rust>();
    |                                               ^^^^^^^^^ `u128` cannot be safely transmuted into `should_reject_repr_rust::braces::repr_rust` in the defining scope of `assert::Context`.
    |
-   = help: the trait `BikeshedIntrinsicFrom<u128, assert::Context, true, true, true, true>` is not implemented for `should_reject_repr_rust::braces::repr_rust`
+   = help: the trait `BikeshedIntrinsicFrom<u128, assert::Context, Assume { alignment: true, lifetimes: true, safety: true, validity: true }>` is not implemented for `should_reject_repr_rust::braces::repr_rust`
 note: required by a bound in `is_maybe_transmutable`
   --> $DIR/should_require_well_defined_layout.rs:13:14
    |
-LL |     pub fn is_maybe_transmutable<Src, Dst>()
-   |            --------------------- required by a bound in this
-LL |     where
-LL |         Dst: BikeshedIntrinsicFrom<Src, Context, true, true, true, true>
-   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `is_maybe_transmutable`
+LL |       pub fn is_maybe_transmutable<Src, Dst>()
+   |              --------------------- required by a bound in this
+LL |       where
+LL |           Dst: BikeshedIntrinsicFrom<Src, Context, {
+   |  ______________^
+LL | |             Assume {
+LL | |                 alignment: true,
+LL | |                 lifetimes: true,
+...  |
+LL | |             }
+LL | |         }>
+   | |__________^ required by this bound in `is_maybe_transmutable`
 
 error[E0277]: `aligned::repr_rust` cannot be safely transmuted into `()` in the defining scope of `assert::Context`.
-  --> $DIR/should_require_well_defined_layout.rs:39:52
+  --> $DIR/should_require_well_defined_layout.rs:46:52
    |
 LL |         assert::is_maybe_transmutable::<repr_rust, ()>();
    |                                                    ^^ `aligned::repr_rust` cannot be safely transmuted into `()` in the defining scope of `assert::Context`.
    |
-   = help: the trait `BikeshedIntrinsicFrom<aligned::repr_rust, assert::Context, true, true, true, true>` is not implemented for `()`
+   = help: the trait `BikeshedIntrinsicFrom<aligned::repr_rust, assert::Context, Assume { alignment: true, lifetimes: true, safety: true, validity: true }>` is not implemented for `()`
 note: required by a bound in `is_maybe_transmutable`
   --> $DIR/should_require_well_defined_layout.rs:13:14
    |
-LL |     pub fn is_maybe_transmutable<Src, Dst>()
-   |            --------------------- required by a bound in this
-LL |     where
-LL |         Dst: BikeshedIntrinsicFrom<Src, Context, true, true, true, true>
-   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `is_maybe_transmutable`
+LL |       pub fn is_maybe_transmutable<Src, Dst>()
+   |              --------------------- required by a bound in this
+LL |       where
+LL |           Dst: BikeshedIntrinsicFrom<Src, Context, {
+   |  ______________^
+LL | |             Assume {
+LL | |                 alignment: true,
+LL | |                 lifetimes: true,
+...  |
+LL | |             }
+LL | |         }>
+   | |__________^ required by this bound in `is_maybe_transmutable`
 
 error[E0277]: `u128` cannot be safely transmuted into `aligned::repr_rust` in the defining scope of `assert::Context`.
-  --> $DIR/should_require_well_defined_layout.rs:40:47
+  --> $DIR/should_require_well_defined_layout.rs:47:47
    |
 LL |         assert::is_maybe_transmutable::<u128, repr_rust>();
    |                                               ^^^^^^^^^ `u128` cannot be safely transmuted into `aligned::repr_rust` in the defining scope of `assert::Context`.
    |
-   = help: the trait `BikeshedIntrinsicFrom<u128, assert::Context, true, true, true, true>` is not implemented for `aligned::repr_rust`
+   = help: the trait `BikeshedIntrinsicFrom<u128, assert::Context, Assume { alignment: true, lifetimes: true, safety: true, validity: true }>` is not implemented for `aligned::repr_rust`
 note: required by a bound in `is_maybe_transmutable`
   --> $DIR/should_require_well_defined_layout.rs:13:14
    |
-LL |     pub fn is_maybe_transmutable<Src, Dst>()
-   |            --------------------- required by a bound in this
-LL |     where
-LL |         Dst: BikeshedIntrinsicFrom<Src, Context, true, true, true, true>
-   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `is_maybe_transmutable`
+LL |       pub fn is_maybe_transmutable<Src, Dst>()
+   |              --------------------- required by a bound in this
+LL |       where
+LL |           Dst: BikeshedIntrinsicFrom<Src, Context, {
+   |  ______________^
+LL | |             Assume {
+LL | |                 alignment: true,
+LL | |                 lifetimes: true,
+...  |
+LL | |             }
+LL | |         }>
+   | |__________^ required by this bound in `is_maybe_transmutable`
 
 error[E0277]: `packed::repr_rust` cannot be safely transmuted into `()` in the defining scope of `assert::Context`.
-  --> $DIR/should_require_well_defined_layout.rs:45:52
+  --> $DIR/should_require_well_defined_layout.rs:52:52
    |
 LL |         assert::is_maybe_transmutable::<repr_rust, ()>();
    |                                                    ^^ `packed::repr_rust` cannot be safely transmuted into `()` in the defining scope of `assert::Context`.
    |
-   = help: the trait `BikeshedIntrinsicFrom<packed::repr_rust, assert::Context, true, true, true, true>` is not implemented for `()`
+   = help: the trait `BikeshedIntrinsicFrom<packed::repr_rust, assert::Context, Assume { alignment: true, lifetimes: true, safety: true, validity: true }>` is not implemented for `()`
 note: required by a bound in `is_maybe_transmutable`
   --> $DIR/should_require_well_defined_layout.rs:13:14
    |
-LL |     pub fn is_maybe_transmutable<Src, Dst>()
-   |            --------------------- required by a bound in this
-LL |     where
-LL |         Dst: BikeshedIntrinsicFrom<Src, Context, true, true, true, true>
-   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `is_maybe_transmutable`
+LL |       pub fn is_maybe_transmutable<Src, Dst>()
+   |              --------------------- required by a bound in this
+LL |       where
+LL |           Dst: BikeshedIntrinsicFrom<Src, Context, {
+   |  ______________^
+LL | |             Assume {
+LL | |                 alignment: true,
+LL | |                 lifetimes: true,
+...  |
+LL | |             }
+LL | |         }>
+   | |__________^ required by this bound in `is_maybe_transmutable`
 
 error[E0277]: `u128` cannot be safely transmuted into `packed::repr_rust` in the defining scope of `assert::Context`.
-  --> $DIR/should_require_well_defined_layout.rs:46:47
+  --> $DIR/should_require_well_defined_layout.rs:53:47
    |
 LL |         assert::is_maybe_transmutable::<u128, repr_rust>();
    |                                               ^^^^^^^^^ `u128` cannot be safely transmuted into `packed::repr_rust` in the defining scope of `assert::Context`.
    |
-   = help: the trait `BikeshedIntrinsicFrom<u128, assert::Context, true, true, true, true>` is not implemented for `packed::repr_rust`
+   = help: the trait `BikeshedIntrinsicFrom<u128, assert::Context, Assume { alignment: true, lifetimes: true, safety: true, validity: true }>` is not implemented for `packed::repr_rust`
 note: required by a bound in `is_maybe_transmutable`
   --> $DIR/should_require_well_defined_layout.rs:13:14
    |
-LL |     pub fn is_maybe_transmutable<Src, Dst>()
-   |            --------------------- required by a bound in this
-LL |     where
-LL |         Dst: BikeshedIntrinsicFrom<Src, Context, true, true, true, true>
-   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `is_maybe_transmutable`
+LL |       pub fn is_maybe_transmutable<Src, Dst>()
+   |              --------------------- required by a bound in this
+LL |       where
+LL |           Dst: BikeshedIntrinsicFrom<Src, Context, {
+   |  ______________^
+LL | |             Assume {
+LL | |                 alignment: true,
+LL | |                 lifetimes: true,
+...  |
+LL | |             }
+LL | |         }>
+   | |__________^ required by this bound in `is_maybe_transmutable`
 
 error[E0277]: `nested::repr_c` cannot be safely transmuted into `()` in the defining scope of `assert::Context`.
-  --> $DIR/should_require_well_defined_layout.rs:52:49
+  --> $DIR/should_require_well_defined_layout.rs:59:49
    |
 LL |         assert::is_maybe_transmutable::<repr_c, ()>();
    |                                                 ^^ `nested::repr_c` cannot be safely transmuted into `()` in the defining scope of `assert::Context`.
    |
-   = help: the trait `BikeshedIntrinsicFrom<nested::repr_c, assert::Context, true, true, true, true>` is not implemented for `()`
+   = help: the trait `BikeshedIntrinsicFrom<nested::repr_c, assert::Context, Assume { alignment: true, lifetimes: true, safety: true, validity: true }>` is not implemented for `()`
 note: required by a bound in `is_maybe_transmutable`
   --> $DIR/should_require_well_defined_layout.rs:13:14
    |
-LL |     pub fn is_maybe_transmutable<Src, Dst>()
-   |            --------------------- required by a bound in this
-LL |     where
-LL |         Dst: BikeshedIntrinsicFrom<Src, Context, true, true, true, true>
-   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `is_maybe_transmutable`
+LL |       pub fn is_maybe_transmutable<Src, Dst>()
+   |              --------------------- required by a bound in this
+LL |       where
+LL |           Dst: BikeshedIntrinsicFrom<Src, Context, {
+   |  ______________^
+LL | |             Assume {
+LL | |                 alignment: true,
+LL | |                 lifetimes: true,
+...  |
+LL | |             }
+LL | |         }>
+   | |__________^ required by this bound in `is_maybe_transmutable`
 
 error[E0277]: `u128` cannot be safely transmuted into `nested::repr_c` in the defining scope of `assert::Context`.
-  --> $DIR/should_require_well_defined_layout.rs:53:47
+  --> $DIR/should_require_well_defined_layout.rs:60:47
    |
 LL |         assert::is_maybe_transmutable::<u128, repr_c>();
    |                                               ^^^^^^ `u128` cannot be safely transmuted into `nested::repr_c` in the defining scope of `assert::Context`.
    |
-   = help: the trait `BikeshedIntrinsicFrom<u128, assert::Context, true, true, true, true>` is not implemented for `nested::repr_c`
+   = help: the trait `BikeshedIntrinsicFrom<u128, assert::Context, Assume { alignment: true, lifetimes: true, safety: true, validity: true }>` is not implemented for `nested::repr_c`
 note: required by a bound in `is_maybe_transmutable`
   --> $DIR/should_require_well_defined_layout.rs:13:14
    |
-LL |     pub fn is_maybe_transmutable<Src, Dst>()
-   |            --------------------- required by a bound in this
-LL |     where
-LL |         Dst: BikeshedIntrinsicFrom<Src, Context, true, true, true, true>
-   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `is_maybe_transmutable`
+LL |       pub fn is_maybe_transmutable<Src, Dst>()
+   |              --------------------- required by a bound in this
+LL |       where
+LL |           Dst: BikeshedIntrinsicFrom<Src, Context, {
+   |  ______________^
+LL | |             Assume {
+LL | |                 alignment: true,
+LL | |                 lifetimes: true,
+...  |
+LL | |             }
+LL | |         }>
+   | |__________^ required by this bound in `is_maybe_transmutable`
 
 error: aborting due to 12 previous errors
 
diff --git a/src/test/ui/transmutability/structs/should_order_fields_correctly.rs b/src/test/ui/transmutability/structs/should_order_fields_correctly.rs
index db49b914fe0..28724562bad 100644
--- a/src/test/ui/transmutability/structs/should_order_fields_correctly.rs
+++ b/src/test/ui/transmutability/structs/should_order_fields_correctly.rs
@@ -6,12 +6,17 @@
 #![allow(dead_code)]
 
 mod assert {
-    use std::mem::BikeshedIntrinsicFrom;
+    use std::mem::{Assume, BikeshedIntrinsicFrom};
     pub struct Context;
 
     pub fn is_transmutable<Src, Dst>()
     where
-        Dst: BikeshedIntrinsicFrom<Src, Context, true, true, true, true>
+        Dst: BikeshedIntrinsicFrom<Src, Context, {
+            Assume::ALIGNMENT
+                .and(Assume::LIFETIMES)
+                .and(Assume::SAFETY)
+                .and(Assume::VALIDITY)
+        }>
     {}
 }