Rollup merge of #56220 - estebank:suggest-lifetime-move, r=nikomatsakis

Suggest appropriate place for lifetime when declared after type arguments

7 files changed, 83 insertions, 0 deletions

diff --git a/src/test/ui/parser/issue-14303-enum.stderr b/src/test/ui/parser/issue-14303-enum.stderr
index 7d546cb2180..622066a94f8 100644
--- a/src/test/ui/parser/issue-14303-enum.stderr
+++ b/src/test/ui/parser/issue-14303-enum.stderr
@@ -3,6 +3,10 @@ error: lifetime parameters must be declared prior to type parameters
    |
 LL | enum X<'a, T, 'b> {
    |               ^^
+help: move the lifetime parameter prior to the first type parameter
+   |
+LL | enum X<'a, 'b, T> {
+   |            ^^^ --
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/parser/issue-14303-fn-def.stderr b/src/test/ui/parser/issue-14303-fn-def.stderr
index c7b57f36376..630c9cb40de 100644
--- a/src/test/ui/parser/issue-14303-fn-def.stderr
+++ b/src/test/ui/parser/issue-14303-fn-def.stderr
@@ -3,6 +3,10 @@ error: lifetime parameters must be declared prior to type parameters
    |
 LL | fn foo<'a, T, 'b>(x: &'a T) {}
    |               ^^
+help: move the lifetime parameter prior to the first type parameter
+   |
+LL | fn foo<'a, 'b, T>(x: &'a T) {}
+   |            ^^^ --
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/parser/issue-14303-impl.stderr b/src/test/ui/parser/issue-14303-impl.stderr
index 0b7016eb7f7..2e3181de902 100644
--- a/src/test/ui/parser/issue-14303-impl.stderr
+++ b/src/test/ui/parser/issue-14303-impl.stderr
@@ -3,6 +3,10 @@ error: lifetime parameters must be declared prior to type parameters
    |
 LL | impl<'a, T, 'b> X {}
    |             ^^
+help: move the lifetime parameter prior to the first type parameter
+   |
+LL | impl<'a, 'b, T> X {}
+   |          ^^^ --
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/parser/issue-14303-struct.stderr b/src/test/ui/parser/issue-14303-struct.stderr
index 4a4b6789194..c6b33120c18 100644
--- a/src/test/ui/parser/issue-14303-struct.stderr
+++ b/src/test/ui/parser/issue-14303-struct.stderr
@@ -3,6 +3,10 @@ error: lifetime parameters must be declared prior to type parameters
    |
 LL | struct X<'a, T, 'b> {
    |                 ^^
+help: move the lifetime parameter prior to the first type parameter
+   |
+LL | struct X<'a, 'b, T> {
+   |              ^^^ --
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/parser/issue-14303-trait.stderr b/src/test/ui/parser/issue-14303-trait.stderr
index ab5cc5655bb..6d00f284bbb 100644
--- a/src/test/ui/parser/issue-14303-trait.stderr
+++ b/src/test/ui/parser/issue-14303-trait.stderr
@@ -3,6 +3,10 @@ error: lifetime parameters must be declared prior to type parameters
    |
 LL | trait Foo<'a, T, 'b> {}
    |                  ^^
+help: move the lifetime parameter prior to the first type parameter
+   |
+LL | trait Foo<'a, 'b, T> {}
+   |               ^^^ --
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/suggestions/suggest-move-lifetimes.rs b/src/test/ui/suggestions/suggest-move-lifetimes.rs
new file mode 100644
index 00000000000..5051a406078
--- /dev/null
+++ b/src/test/ui/suggestions/suggest-move-lifetimes.rs
@@ -0,0 +1,21 @@
+struct A<T, 'a> {
+    t: &'a T,
+}
+
+struct B<T, 'a, U> {
+    t: &'a T,
+    u: U,
+}
+
+struct C<T, U, 'a> {
+    t: &'a T,
+    u: U,
+}
+
+struct D<T, U, 'a, 'b, V, 'c> {
+    t: &'a T,
+    u: &'b U,
+    v: &'c V,
+}
+
+fn main() {}
diff --git a/src/test/ui/suggestions/suggest-move-lifetimes.stderr b/src/test/ui/suggestions/suggest-move-lifetimes.stderr
new file mode 100644
index 00000000000..f3d6469b512
--- /dev/null
+++ b/src/test/ui/suggestions/suggest-move-lifetimes.stderr
@@ -0,0 +1,42 @@
+error: lifetime parameters must be declared prior to type parameters
+  --> $DIR/suggest-move-lifetimes.rs:1:13
+   |
+LL | struct A<T, 'a> {
+   |             ^^
+help: move the lifetime parameter prior to the first type parameter
+   |
+LL | struct A<'a, T> {
+   |          ^^^ --
+
+error: lifetime parameters must be declared prior to type parameters
+  --> $DIR/suggest-move-lifetimes.rs:5:13
+   |
+LL | struct B<T, 'a, U> {
+   |             ^^
+help: move the lifetime parameter prior to the first type parameter
+   |
+LL | struct B<'a, T, U> {
+   |          ^^^   --
+
+error: lifetime parameters must be declared prior to type parameters
+  --> $DIR/suggest-move-lifetimes.rs:10:16
+   |
+LL | struct C<T, U, 'a> {
+   |                ^^
+help: move the lifetime parameter prior to the first type parameter
+   |
+LL | struct C<'a, T, U> {
+   |          ^^^    --
+
+error: lifetime parameters must be declared prior to type parameters
+  --> $DIR/suggest-move-lifetimes.rs:15:16
+   |
+LL | struct D<T, U, 'a, 'b, V, 'c> {
+   |                ^^  ^^     ^^
+help: move the lifetime parameter prior to the first type parameter
+   |
+LL | struct D<'a, 'b, 'c, T, U, V> {
+   |          ^^^ ^^^ ^^^      ---
+
+error: aborting due to 4 previous errors
+