Handle Fn family trait call errror

7 files changed, 14 insertions, 7 deletions

diff --git a/src/test/ui/consts/issue-28113.rs b/src/test/ui/consts/issue-28113.rs
index 1d93d454af7..f8131c9f3b7 100644
--- a/src/test/ui/consts/issue-28113.rs
+++ b/src/test/ui/consts/issue-28113.rs
@@ -2,7 +2,7 @@
 
 const X: u8 =
     || -> u8 { 5 }()
-    //~^ ERROR cannot call non-const fn
+    //~^ ERROR cannot call non-const closure
 ;
 
 fn main() {}
diff --git a/src/test/ui/consts/issue-28113.stderr b/src/test/ui/consts/issue-28113.stderr
index 75fcc010a04..7ad1f752eb0 100644
--- a/src/test/ui/consts/issue-28113.stderr
+++ b/src/test/ui/consts/issue-28113.stderr
@@ -1,9 +1,10 @@
-error[E0015]: cannot call non-const fn `<[closure@$DIR/issue-28113.rs:4:5: 4:19] as Fn<()>>::call` in constants
+error[E0015]: cannot call non-const closure in constants
   --> $DIR/issue-28113.rs:4:5
    |
 LL |     || -> u8 { 5 }()
    |     ^^^^^^^^^^^^^^^^
    |
+   = note: closures need an RFC before allowed to be called in constants
    = note: calls in constants are limited to constant functions, tuple structs and tuple variants
 
 error: aborting due to previous error
diff --git a/src/test/ui/consts/issue-56164.rs b/src/test/ui/consts/issue-56164.rs
index af65720916c..9c673d20b2a 100644
--- a/src/test/ui/consts/issue-56164.rs
+++ b/src/test/ui/consts/issue-56164.rs
@@ -1,7 +1,7 @@
 #![feature(const_fn_fn_ptr_basics)]
 
 const fn foo() { (||{})() }
-//~^ ERROR cannot call non-const fn
+//~^ ERROR cannot call non-const closure
 
 const fn bad(input: fn()) {
     input()
diff --git a/src/test/ui/consts/issue-56164.stderr b/src/test/ui/consts/issue-56164.stderr
index af5d44d4814..62a7c7db6b8 100644
--- a/src/test/ui/consts/issue-56164.stderr
+++ b/src/test/ui/consts/issue-56164.stderr
@@ -1,9 +1,10 @@
-error[E0015]: cannot call non-const fn `<[closure@$DIR/issue-56164.rs:3:18: 3:24] as Fn<()>>::call` in constant functions
+error[E0015]: cannot call non-const closure in constant functions
   --> $DIR/issue-56164.rs:3:18
    |
 LL | const fn foo() { (||{})() }
    |                  ^^^^^^^^
    |
+   = note: closures need an RFC before allowed to be called in constant functions
    = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
 
 error: function pointers are not allowed in const fn
diff --git a/src/test/ui/consts/issue-68542-closure-in-array-len.rs b/src/test/ui/consts/issue-68542-closure-in-array-len.rs
index 44f44da234a..37958e7919d 100644
--- a/src/test/ui/consts/issue-68542-closure-in-array-len.rs
+++ b/src/test/ui/consts/issue-68542-closure-in-array-len.rs
@@ -3,7 +3,7 @@
 // in the length part of an array.
 
 struct Bug {
-    a: [(); (|| { 0 })()] //~ ERROR cannot call non-const fn
+    a: [(); (|| { 0 })()] //~ ERROR cannot call non-const closure
 }
 
 fn main() {}
diff --git a/src/test/ui/consts/issue-68542-closure-in-array-len.stderr b/src/test/ui/consts/issue-68542-closure-in-array-len.stderr
index 3787138afc3..74fbbc680f7 100644
--- a/src/test/ui/consts/issue-68542-closure-in-array-len.stderr
+++ b/src/test/ui/consts/issue-68542-closure-in-array-len.stderr
@@ -1,9 +1,10 @@
-error[E0015]: cannot call non-const fn `<[closure@$DIR/issue-68542-closure-in-array-len.rs:6:13: 6:23] as Fn<()>>::call` in constants
+error[E0015]: cannot call non-const closure in constants
   --> $DIR/issue-68542-closure-in-array-len.rs:6:13
    |
 LL |     a: [(); (|| { 0 })()]
    |             ^^^^^^^^^^^^
    |
+   = note: closures need an RFC before allowed to be called in constants
    = note: calls in constants are limited to constant functions, tuple structs and tuple variants
 
 error: aborting due to previous error
diff --git a/src/test/ui/consts/unstable-const-fn-in-libcore.stderr b/src/test/ui/consts/unstable-const-fn-in-libcore.stderr
index 435141134cb..4ef25bd1334 100644
--- a/src/test/ui/consts/unstable-const-fn-in-libcore.stderr
+++ b/src/test/ui/consts/unstable-const-fn-in-libcore.stderr
@@ -1,10 +1,14 @@
-error[E0015]: cannot call non-const fn `<F as FnOnce<()>>::call_once` in constant functions
+error[E0015]: cannot call non-const closure in constant functions
   --> $DIR/unstable-const-fn-in-libcore.rs:24:26
    |
 LL |             Opt::None => f(),
    |                          ^^^
    |
    = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
+help: consider further restricting this bound
+   |
+LL |     const fn unwrap_or_else<F: FnOnce() -> T + ~const std::ops::FnOnce<()>>(self, f: F) -> T {
+   |                                              +++++++++++++++++++++++++++++
 
 error[E0493]: destructors cannot be evaluated at compile-time
   --> $DIR/unstable-const-fn-in-libcore.rs:19:53