Suggestion to wrap inner types using `allocator_api` in tuple

2 files changed, 58 insertions, 0 deletions

diff --git a/src/test/ui/stability-attribute/suggest-vec-allocator-api.rs b/src/test/ui/stability-attribute/suggest-vec-allocator-api.rs
new file mode 100644
index 00000000000..fac52ab77c6
--- /dev/null
+++ b/src/test/ui/stability-attribute/suggest-vec-allocator-api.rs
@@ -0,0 +1,9 @@
+fn main() {
+    let _: Vec<u8, _> = vec![]; //~ ERROR use of unstable library feature 'allocator_api'
+    #[rustfmt::skip]
+    let _: Vec<
+        String,
+        _> = vec![]; //~ ERROR use of unstable library feature 'allocator_api'
+    let _ = Vec::<u16, _>::new(); //~ ERROR use of unstable library feature 'allocator_api'
+    let _boxed: Box<u32, _> = Box::new(10); //~ ERROR use of unstable library feature 'allocator_api'
+}
diff --git a/src/test/ui/stability-attribute/suggest-vec-allocator-api.stderr b/src/test/ui/stability-attribute/suggest-vec-allocator-api.stderr
new file mode 100644
index 00000000000..41e5787b8c2
--- /dev/null
+++ b/src/test/ui/stability-attribute/suggest-vec-allocator-api.stderr
@@ -0,0 +1,49 @@
+error[E0658]: use of unstable library feature 'allocator_api'
+  --> $DIR/suggest-vec-allocator-api.rs:2:20
+   |
+LL |     let _: Vec<u8, _> = vec![];
+   |                ----^
+   |                |
+   |                help: consider wrapping the inner types in tuple: `(u8, _)`
+   |
+   = note: see issue #32838 <https://github.com/rust-lang/rust/issues/32838> for more information
+   = help: add `#![feature(allocator_api)]` to the crate attributes to enable
+
+error[E0658]: use of unstable library feature 'allocator_api'
+  --> $DIR/suggest-vec-allocator-api.rs:6:9
+   |
+LL |         _> = vec![];
+   |         ^
+   |
+   = note: see issue #32838 <https://github.com/rust-lang/rust/issues/32838> for more information
+   = help: add `#![feature(allocator_api)]` to the crate attributes to enable
+help: consider wrapping the inner types in tuple
+   |
+LL ~     let _: Vec<(
+LL +         String,
+LL ~         _)> = vec![];
+   |
+
+error[E0658]: use of unstable library feature 'allocator_api'
+  --> $DIR/suggest-vec-allocator-api.rs:8:26
+   |
+LL |     let _boxed: Box<u32, _> = Box::new(10);
+   |                          ^
+   |
+   = note: see issue #32838 <https://github.com/rust-lang/rust/issues/32838> for more information
+   = help: add `#![feature(allocator_api)]` to the crate attributes to enable
+
+error[E0658]: use of unstable library feature 'allocator_api'
+  --> $DIR/suggest-vec-allocator-api.rs:7:24
+   |
+LL |     let _ = Vec::<u16, _>::new();
+   |                   -----^
+   |                   |
+   |                   help: consider wrapping the inner types in tuple: `(u16, _)`
+   |
+   = note: see issue #32838 <https://github.com/rust-lang/rust/issues/32838> for more information
+   = help: add `#![feature(allocator_api)]` to the crate attributes to enable
+
+error: aborting due to 4 previous errors
+
+For more information about this error, try `rustc --explain E0658`.