Clarify conversion diagnostic (#5052)

TODO to resolve whether it should conditionally say "object of"
depending on the category

---------

Co-authored-by: Josh L <josh11b@users.noreply.github.com>

toolchain/check/convert.cpp

@@ -1195,11 +1195,13 @@ auto Convert(Context& context, SemIR::LocId loc_id, SemIR::InstId expr_id,
       if (!target.diagnose) {
         return context.emitter().BuildSuppressed();
       }
+      // TODO: Should this message change to say "object of type" when
+      // converting from a reference expression?
       CARBON_DIAGNOSTIC(ImplicitAsConversionFailure, Error,
-                        "cannot implicitly convert from {0} to {1}",
+                        "cannot implicitly convert value of type {0} to {1}",
                         TypeOfInstId, SemIR::TypeId);
       CARBON_DIAGNOSTIC(ExplicitAsConversionFailure, Error,
-                        "cannot convert from {0} to {1} with `as`",
+                        "cannot convert value of type {0} to {1} with `as`",
                         TypeOfInstId, SemIR::TypeId);
       return context.emitter().Build(loc_id,
                                      target.kind == ConversionTarget::ExplicitAs

toolchain/check/testdata/array/fail_bound_overflow.carbon

@@ -14,7 +14,7 @@
 // CHECK:STDERR:
 var a: array(i32, 39999999999999999993);
 
-// CHECK:STDERR: fail_bound_overflow.carbon:[[@LINE+7]]:14: error: cannot implicitly convert from `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_bound_overflow.carbon:[[@LINE+7]]:14: error: cannot implicitly convert value of type `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var b: array(1, 39999999999999999993);
 // CHECK:STDERR:              ^
 // CHECK:STDERR: fail_bound_overflow.carbon:[[@LINE+4]]:14: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/array/fail_invalid_type.carbon

@@ -8,7 +8,7 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/array/fail_invalid_type.carbon
 
-// CHECK:STDERR: fail_invalid_type.carbon:[[@LINE+7]]:14: error: cannot implicitly convert from `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_invalid_type.carbon:[[@LINE+7]]:14: error: cannot implicitly convert value of type `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var a: array(1, 1);
 // CHECK:STDERR:              ^
 // CHECK:STDERR: fail_invalid_type.carbon:[[@LINE+4]]:14: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/array/fail_type_mismatch.carbon

@@ -8,7 +8,7 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/array/fail_type_mismatch.carbon
 
-// CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+7]]:24: error: cannot implicitly convert from `String` to `i32` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+7]]:24: error: cannot implicitly convert value of type `String` to `i32` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var a: array(i32, 3) = (1, "Hello", "World");
 // CHECK:STDERR:                        ^~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+4]]:24: note: type `String` does not implement interface `Core.ImplicitAs(i32)` [MissingImplInMemberAccessNote]
@@ -18,7 +18,7 @@
 var a: array(i32, 3) = (1, "Hello", "World");
 
 var t1: (i32, String, String);
-// CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+7]]:24: error: cannot implicitly convert from `String` to `i32` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+7]]:24: error: cannot implicitly convert value of type `String` to `i32` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var b: array(i32, 3) = t1;
 // CHECK:STDERR:                        ^~
 // CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+4]]:24: note: type `String` does not implement interface `Core.ImplicitAs(i32)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/as/adapter_conversion.carbon

@@ -154,7 +154,7 @@ class B {
 // We do not try to implicitly convert from the first operand of `as` to the
 // adapted type of the second operand.
 
-// CHECK:STDERR: fail_adapt_init_from_struct.carbon:[[@LINE+7]]:12: error: cannot convert from `{.x: Core.IntLiteral}` to `B` with `as` [ExplicitAsConversionFailure]
+// CHECK:STDERR: fail_adapt_init_from_struct.carbon:[[@LINE+7]]:12: error: cannot convert value of type `{.x: Core.IntLiteral}` to `B` with `as` [ExplicitAsConversionFailure]
 // CHECK:STDERR: var b: B = {.x = 1} as B;
 // CHECK:STDERR:            ^~~~~~~~~~~~~
 // CHECK:STDERR: fail_adapt_init_from_struct.carbon:[[@LINE+4]]:12: note: type `{.x: Core.IntLiteral}` does not implement interface `Core.As(B)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/as/fail_no_conversion.carbon

@@ -8,7 +8,7 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/as/fail_no_conversion.carbon
 
-// CHECK:STDERR: fail_no_conversion.carbon:[[@LINE+7]]:21: error: cannot convert from `Core.IntLiteral` to `(i32, i32)` with `as` [ExplicitAsConversionFailure]
+// CHECK:STDERR: fail_no_conversion.carbon:[[@LINE+7]]:21: error: cannot convert value of type `Core.IntLiteral` to `(i32, i32)` with `as` [ExplicitAsConversionFailure]
 // CHECK:STDERR: let n: (i32, i32) = 1 as (i32, i32);
 // CHECK:STDERR:                     ^~~~~~~~~~~~~~~
 // CHECK:STDERR: fail_no_conversion.carbon:[[@LINE+4]]:21: note: type `Core.IntLiteral` does not implement interface `Core.As((i32, i32))` [MissingImplInMemberAccessNote]

toolchain/check/testdata/as/fail_not_type.carbon

@@ -8,7 +8,7 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/as/fail_not_type.carbon
 
-// CHECK:STDERR: fail_not_type.carbon:[[@LINE+7]]:19: error: cannot implicitly convert from `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_not_type.carbon:[[@LINE+7]]:19: error: cannot implicitly convert value of type `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
 // CHECK:STDERR: let n: i32 = 1 as 2;
 // CHECK:STDERR:                   ^
 // CHECK:STDERR: fail_not_type.carbon:[[@LINE+4]]:19: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/basics/fail_non_type_as_type.carbon

@@ -8,7 +8,7 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/basics/fail_non_type_as_type.carbon
 
-// CHECK:STDERR: fail_non_type_as_type.carbon:[[@LINE+7]]:1: error: cannot implicitly convert from `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_non_type_as_type.carbon:[[@LINE+7]]:1: error: cannot implicitly convert value of type `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var x: type = 42;
 // CHECK:STDERR: ^~~~~~~~~~~
 // CHECK:STDERR: fail_non_type_as_type.carbon:[[@LINE+4]]:1: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/builtin_conversions/no_prelude/fail_convert_class_type_to_generic_facet_value.carbon

@@ -35,7 +35,7 @@ impl ImplsGeneric as Generic(GenericParam) {
 fn CallGenericMethod(T:! type, U:! Generic(T)) {}
 
 fn G() {
-  // CHECK:STDERR: fail_convert_class_type_to_generic_facet_value.carbon:[[@LINE+10]]:3: error: cannot implicitly convert from `type` to `Generic(WrongGenericParam)` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_convert_class_type_to_generic_facet_value.carbon:[[@LINE+10]]:3: error: cannot implicitly convert value of type `type` to `Generic(WrongGenericParam)` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   CallGenericMethod(WrongGenericParam, ImplsGeneric);
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   // CHECK:STDERR: fail_convert_class_type_to_generic_facet_value.carbon:[[@LINE+7]]:3: note: type `type` does not implement interface `Core.ImplicitAs(Generic(WrongGenericParam))` [MissingImplInMemberAccessNote]

toolchain/check/testdata/builtin_conversions/no_prelude/fail_convert_facet_value_shouldnt_know_concrete_type.carbon

@@ -36,7 +36,7 @@ impl Goat as Eats {}
 fn Feed(e:! Eats) {}
 
 fn F() {
-  // CHECK:STDERR: fail_convert_facet_value_shouldnt_know_concrete_type.carbon:[[@LINE+10]]:3: error: cannot implicitly convert from `Animal` to `Eats` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_convert_facet_value_shouldnt_know_concrete_type.carbon:[[@LINE+10]]:3: error: cannot implicitly convert value of type `Animal` to `Eats` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   Feed(Goat as Animal);
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~~
   // CHECK:STDERR: fail_convert_facet_value_shouldnt_know_concrete_type.carbon:[[@LINE+7]]:3: note: type `Animal` does not implement interface `Core.ImplicitAs(Eats)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/builtin_conversions/no_prelude/fail_convert_facet_value_to_missing_impl.carbon

@@ -27,7 +27,7 @@ interface Animal {}
 
 fn Feed[T:! Eats](e: T) {}
 
-// CHECK:STDERR: fail_convert_facet_value_to_missing_impl.carbon:[[@LINE+10]]:37: error: cannot implicitly convert from `type` to `Eats` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_convert_facet_value_to_missing_impl.carbon:[[@LINE+10]]:37: error: cannot implicitly convert value of type `type` to `Eats` [ImplicitAsConversionFailure]
 // CHECK:STDERR: fn HandleAnimal[T:! Animal](a: T) { Feed(a); }
 // CHECK:STDERR:                                     ^~~~~~~
 // CHECK:STDERR: fail_convert_facet_value_to_missing_impl.carbon:[[@LINE+7]]:37: note: type `type` does not implement interface `Core.ImplicitAs(Eats)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/builtin_conversions/no_prelude/fail_convert_type_erased_type_to_facet.carbon

@@ -35,7 +35,7 @@ fn WalkAnimal(a:! Animal) {}
 
 fn F() {
   let x:! type = Goat;
-  // CHECK:STDERR: fail_convert_type_erased_type_to_facet.carbon:[[@LINE+10]]:3: error: cannot implicitly convert from `type` to `Animal` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_convert_type_erased_type_to_facet.carbon:[[@LINE+10]]:3: error: cannot implicitly convert value of type `type` to `Animal` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   WalkAnimal(x);
   // CHECK:STDERR:   ^~~~~~~~~~~~~
   // CHECK:STDERR: fail_convert_type_erased_type_to_facet.carbon:[[@LINE+7]]:3: note: type `type` does not implement interface `Core.ImplicitAs(Animal)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/builtins/int/convert.carbon

@@ -47,7 +47,7 @@ import library "int_ops";
 
 fn F() {
   // Ensure our testing machinery works.
-  // CHECK:STDERR: fail_self_test.carbon:[[@LINE+7]]:3: error: cannot convert from `Expect(0)` to `Expect(1)` with `as` [ExplicitAsConversionFailure]
+  // CHECK:STDERR: fail_self_test.carbon:[[@LINE+7]]:3: error: cannot convert value of type `Expect(0)` to `Expect(1)` with `as` [ExplicitAsConversionFailure]
   // CHECK:STDERR:   Test(Int32ToInt32(0)) as Expect(1 as i32);
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   // CHECK:STDERR: fail_self_test.carbon:[[@LINE+4]]:3: note: type `Expect(0)` does not implement interface `Core.As(Expect(1))` [MissingImplInMemberAccessNote]

toolchain/check/testdata/class/adapter/extend_adapt.carbon

@@ -48,7 +48,7 @@ class SomeClassAdapter {
 }
 
 fn F(a: SomeClassAdapter) {
-  // CHECK:STDERR: fail_todo_method_access.carbon:[[@LINE+10]]:3: error: cannot implicitly convert from `SomeClassAdapter` to `SomeClass` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_todo_method_access.carbon:[[@LINE+10]]:3: error: cannot implicitly convert value of type `SomeClassAdapter` to `SomeClass` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   a.F();
   // CHECK:STDERR:   ^
   // CHECK:STDERR: fail_todo_method_access.carbon:[[@LINE+7]]:3: note: type `SomeClassAdapter` does not implement interface `Core.ImplicitAs(SomeClass)` [MissingImplInMemberAccessNote]
@@ -75,7 +75,7 @@ class SomeClassAdapter {
 }
 
 fn F(a: SomeClassAdapter) -> i32 {
-  // CHECK:STDERR: fail_todo_field_access.carbon:[[@LINE+7]]:10: error: cannot implicitly convert from `SomeClassAdapter` to `SomeClass` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_todo_field_access.carbon:[[@LINE+7]]:10: error: cannot implicitly convert value of type `SomeClassAdapter` to `SomeClass` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   return a.b;
   // CHECK:STDERR:          ^~~
   // CHECK:STDERR: fail_todo_field_access.carbon:[[@LINE+4]]:10: note: type `SomeClassAdapter` does not implement interface `Core.ImplicitAs(SomeClass)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/class/adapter/fail_adapt_bad_decl.carbon

@@ -13,7 +13,7 @@
 library "[[@TEST_NAME]]";
 
 class Bad {
-  // CHECK:STDERR: fail_not_type.carbon:[[@LINE+7]]:3: error: cannot implicitly convert from `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_not_type.carbon:[[@LINE+7]]:3: error: cannot implicitly convert value of type `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   adapt 100;
   // CHECK:STDERR:   ^~~~~~~~~~
   // CHECK:STDERR: fail_not_type.carbon:[[@LINE+4]]:3: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]
@@ -34,7 +34,7 @@ fn Use(b: Bad) { b.F(); }
 library "[[@TEST_NAME]]";
 
 class Bad {
-  // CHECK:STDERR: fail_extend_not_type.carbon:[[@LINE+7]]:3: error: cannot implicitly convert from `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_extend_not_type.carbon:[[@LINE+7]]:3: error: cannot implicitly convert value of type `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   extend adapt 100;
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~
   // CHECK:STDERR: fail_extend_not_type.carbon:[[@LINE+4]]:3: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/class/adapter/init_adapt.carbon

@@ -52,7 +52,7 @@ let a: C = {.a = 1, .b = 2};
 
 // Cannot implicitly convert between a type and an adapter for the type.
 
-// CHECK:STDERR: fail_not_implicit.carbon:[[@LINE+7]]:17: error: cannot implicitly convert from `C` to `AdaptC` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_not_implicit.carbon:[[@LINE+7]]:17: error: cannot implicitly convert value of type `C` to `AdaptC` [ImplicitAsConversionFailure]
 // CHECK:STDERR: let b: AdaptC = a;
 // CHECK:STDERR:                 ^
 // CHECK:STDERR: fail_not_implicit.carbon:[[@LINE+4]]:17: note: type `C` does not implement interface `Core.ImplicitAs(AdaptC)` [MissingImplInMemberAccessNote]
@@ -61,7 +61,7 @@ let a: C = {.a = 1, .b = 2};
 // CHECK:STDERR:
 let b: AdaptC = a;
 
-// CHECK:STDERR: fail_not_implicit.carbon:[[@LINE+7]]:12: error: cannot implicitly convert from `AdaptC` to `C` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_not_implicit.carbon:[[@LINE+7]]:12: error: cannot implicitly convert value of type `AdaptC` to `C` [ImplicitAsConversionFailure]
 // CHECK:STDERR: let c: C = b;
 // CHECK:STDERR:            ^
 // CHECK:STDERR: fail_not_implicit.carbon:[[@LINE+4]]:12: note: type `AdaptC` does not implement interface `Core.ImplicitAs(C)` [MissingImplInMemberAccessNote]
@@ -74,7 +74,7 @@ fn MakeC() -> C;
 
 fn MakeAdaptC() -> AdaptC;
 
-// CHECK:STDERR: fail_not_implicit.carbon:[[@LINE+7]]:1: error: cannot implicitly convert from `C` to `AdaptC` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_not_implicit.carbon:[[@LINE+7]]:1: error: cannot implicitly convert value of type `C` to `AdaptC` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var d: AdaptC = MakeC();
 // CHECK:STDERR: ^~~~~~~~~~~~~
 // CHECK:STDERR: fail_not_implicit.carbon:[[@LINE+4]]:1: note: type `C` does not implement interface `Core.ImplicitAs(AdaptC)` [MissingImplInMemberAccessNote]
@@ -83,7 +83,7 @@ fn MakeAdaptC() -> AdaptC;
 // CHECK:STDERR:
 var d: AdaptC = MakeC();
 
-// CHECK:STDERR: fail_not_implicit.carbon:[[@LINE+7]]:1: error: cannot implicitly convert from `AdaptC` to `C` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_not_implicit.carbon:[[@LINE+7]]:1: error: cannot implicitly convert value of type `AdaptC` to `C` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var e: C = MakeAdaptC();
 // CHECK:STDERR: ^~~~~~~~
 // CHECK:STDERR: fail_not_implicit.carbon:[[@LINE+4]]:1: note: type `AdaptC` does not implement interface `Core.ImplicitAs(C)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/class/fail_base_bad_type.carbon

@@ -28,7 +28,7 @@ fn AccessMemberWithInvalidBaseError(p: DeriveFromError*) -> i32 { return (*p).n;
 library "[[@TEST_NAME]]";
 
 class DeriveFromNonType {
-  // CHECK:STDERR: fail_derive_from_non_type.carbon:[[@LINE+7]]:16: error: cannot implicitly convert from `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_derive_from_non_type.carbon:[[@LINE+7]]:16: error: cannot implicitly convert value of type `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   extend base: 32;
   // CHECK:STDERR:                ^~
   // CHECK:STDERR: fail_derive_from_non_type.carbon:[[@LINE+4]]:16: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]
@@ -76,7 +76,7 @@ class DeriveFromTuple {
   extend base: (Base,);
 }
 
-// CHECK:STDERR: fail_derive_from_tuple.carbon:[[@LINE+7]]:61: error: cannot implicitly convert from `DeriveFromTuple*` to `(Base,)*` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_derive_from_tuple.carbon:[[@LINE+7]]:61: error: cannot implicitly convert value of type `DeriveFromTuple*` to `(Base,)*` [ImplicitAsConversionFailure]
 // CHECK:STDERR: fn ConvertToBadBaseTuple(p: DeriveFromTuple*) -> (Base,)* { return p; }
 // CHECK:STDERR:                                                             ^~~~~~~~~
 // CHECK:STDERR: fail_derive_from_tuple.carbon:[[@LINE+4]]:61: note: type `DeriveFromTuple*` does not implement interface `Core.ImplicitAs((Base,)*)` [MissingImplInMemberAccessNote]
@@ -101,7 +101,7 @@ class DeriveFromStruct {
   extend base: {.a: i32, .b: i32};
 }
 
-// CHECK:STDERR: fail_derive_from_struct.carbon:[[@LINE+7]]:74: error: cannot implicitly convert from `DeriveFromStruct*` to `{.a: i32, .b: i32}*` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_derive_from_struct.carbon:[[@LINE+7]]:74: error: cannot implicitly convert value of type `DeriveFromStruct*` to `{.a: i32, .b: i32}*` [ImplicitAsConversionFailure]
 // CHECK:STDERR: fn ConvertToBadBaseStruct(p: DeriveFromStruct*) -> {.a: i32, .b: i32}* { return p; }
 // CHECK:STDERR:                                                                          ^~~~~~~~~
 // CHECK:STDERR: fail_derive_from_struct.carbon:[[@LINE+4]]:74: note: type `DeriveFromStruct*` does not implement interface `Core.ImplicitAs({.a: i32, .b: i32}*)` [MissingImplInMemberAccessNote]
@@ -134,7 +134,7 @@ class DeriveFromIncomplete {
   extend base: Incomplete;
 }
 
-// CHECK:STDERR: fail_derive_from_incomplete.carbon:[[@LINE+7]]:74: error: cannot implicitly convert from `DeriveFromIncomplete*` to `Incomplete*` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_derive_from_incomplete.carbon:[[@LINE+7]]:74: error: cannot implicitly convert value of type `DeriveFromIncomplete*` to `Incomplete*` [ImplicitAsConversionFailure]
 // CHECK:STDERR: fn ConvertToBadBaseIncomplete(p: DeriveFromIncomplete*) -> Incomplete* { return p; }
 // CHECK:STDERR:                                                                          ^~~~~~~~~
 // CHECK:STDERR: fail_derive_from_incomplete.carbon:[[@LINE+4]]:74: note: type `DeriveFromIncomplete*` does not implement interface `Core.ImplicitAs(Incomplete*)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/class/fail_compound_type_mismatch.carbon

@@ -17,7 +17,7 @@ class B {
 }
 
 fn AccessBInA(a: A) -> i32 {
-  // CHECK:STDERR: fail_compound_type_mismatch.carbon:[[@LINE+7]]:10: error: cannot implicitly convert from `A` to `B` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_compound_type_mismatch.carbon:[[@LINE+7]]:10: error: cannot implicitly convert value of type `A` to `B` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   return a.(B.b);
   // CHECK:STDERR:          ^~~~~~~
   // CHECK:STDERR: fail_compound_type_mismatch.carbon:[[@LINE+4]]:10: note: type `A` does not implement interface `Core.ImplicitAs(B)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/class/fail_derived_to_base.carbon

@@ -21,7 +21,7 @@ class B2 {
   var b: i32;
 }
 
-// CHECK:STDERR: fail_derived_to_base.carbon:[[@LINE+7]]:38: error: cannot implicitly convert from `B2*` to `A1*` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_derived_to_base.carbon:[[@LINE+7]]:38: error: cannot implicitly convert value of type `B2*` to `A1*` [ImplicitAsConversionFailure]
 // CHECK:STDERR: fn ConvertUnrelated(p: B2*) -> A1* { return p; }
 // CHECK:STDERR:                                      ^~~~~~~~~
 // CHECK:STDERR: fail_derived_to_base.carbon:[[@LINE+4]]:38: note: type `B2*` does not implement interface `Core.ImplicitAs(A1*)` [MissingImplInMemberAccessNote]
@@ -32,7 +32,7 @@ fn ConvertUnrelated(p: B2*) -> A1* { return p; }
 
 class Incomplete;
 
-// CHECK:STDERR: fail_derived_to_base.carbon:[[@LINE+7]]:47: error: cannot implicitly convert from `Incomplete*` to `A2*` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_derived_to_base.carbon:[[@LINE+7]]:47: error: cannot implicitly convert value of type `Incomplete*` to `A2*` [ImplicitAsConversionFailure]
 // CHECK:STDERR: fn ConvertIncomplete(p: Incomplete*) -> A2* { return p; }
 // CHECK:STDERR:                                               ^~~~~~~~~
 // CHECK:STDERR: fail_derived_to_base.carbon:[[@LINE+4]]:47: note: type `Incomplete*` does not implement interface `Core.ImplicitAs(A2*)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/class/fail_self.carbon

@@ -43,7 +43,7 @@ class WrongSelf {
 }
 
 fn CallWrongSelf(ws: WrongSelf) {
-  // CHECK:STDERR: fail_self.carbon:[[@LINE+10]]:3: error: cannot implicitly convert from `WrongSelf` to `Class` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_self.carbon:[[@LINE+10]]:3: error: cannot implicitly convert value of type `WrongSelf` to `Class` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   ws.F();
   // CHECK:STDERR:   ^~
   // CHECK:STDERR: fail_self.carbon:[[@LINE+7]]:3: note: type `WrongSelf` does not implement interface `Core.ImplicitAs(Class)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/class/generic/adapt.carbon

@@ -48,7 +48,7 @@ class Adapter {
 
 fn Access(a: Adapter) -> i32 {
   // TODO: This should presumably work, but the design doesn't say how yet.
-  // CHECK:STDERR: fail_todo_extend_adapt_specific_type.carbon:[[@LINE+7]]:10: error: cannot implicitly convert from `Adapter` to `C(i32)` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_todo_extend_adapt_specific_type.carbon:[[@LINE+7]]:10: error: cannot implicitly convert value of type `Adapter` to `C(i32)` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   return a.x;
   // CHECK:STDERR:          ^~~
   // CHECK:STDERR: fail_todo_extend_adapt_specific_type.carbon:[[@LINE+4]]:10: note: type `Adapter` does not implement interface `Core.ImplicitAs(C(i32))` [MissingImplInMemberAccessNote]
@@ -81,7 +81,7 @@ import library "extend_adapt_specific_type_library";
 
 fn ImportedAccess(a: Adapter) -> i32 {
   // TODO: This should presumably work, but the design doesn't say how yet.
-  // CHECK:STDERR: fail_todo_import_extend_adapt_specific_type.carbon:[[@LINE+7]]:10: error: cannot implicitly convert from `Adapter` to `C(i32)` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_todo_import_extend_adapt_specific_type.carbon:[[@LINE+7]]:10: error: cannot implicitly convert value of type `Adapter` to `C(i32)` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   return a.x;
   // CHECK:STDERR:          ^~~
   // CHECK:STDERR: fail_todo_import_extend_adapt_specific_type.carbon:[[@LINE+4]]:10: note: type `Adapter` does not implement interface `Core.ImplicitAs(C(i32))` [MissingImplInMemberAccessNote]

toolchain/check/testdata/class/generic/call.carbon

@@ -55,7 +55,7 @@ library "[[@TEST_NAME]]";
 
 class Class(T:! type, N:! i32) {}
 
-// CHECK:STDERR: fail_no_conversion.carbon:[[@LINE+10]]:8: error: cannot implicitly convert from `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_no_conversion.carbon:[[@LINE+10]]:8: error: cannot implicitly convert value of type `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var a: Class(5, i32*);
 // CHECK:STDERR:        ^~~~~~~~~~~~~~
 // CHECK:STDERR: fail_no_conversion.carbon:[[@LINE+7]]:8: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/class/generic/import.carbon

@@ -55,7 +55,7 @@ import library "foo";
 
 fn Use() {
   // TODO: Include the generic arguments in the formatted type name.
-  // CHECK:STDERR: fail_generic_arg_mismatch.carbon:[[@LINE+7]]:3: error: cannot implicitly convert from `CompleteClass(i32)` to `CompleteClass(i32*)` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_generic_arg_mismatch.carbon:[[@LINE+7]]:3: error: cannot implicitly convert value of type `CompleteClass(i32)` to `CompleteClass(i32*)` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   var v: CompleteClass(i32*) = F();
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~~~~~~~~
   // CHECK:STDERR: fail_generic_arg_mismatch.carbon:[[@LINE+4]]:3: note: type `CompleteClass(i32)` does not implement interface `Core.ImplicitAs(CompleteClass(i32*))` [MissingImplInMemberAccessNote]

toolchain/check/testdata/class/generic/member_access.carbon

@@ -39,7 +39,7 @@ class Class(T:! type) {
 }
 
 fn StaticMemberFunctionCall(T:! type) -> Class(T) {
-  // CHECK:STDERR: fail_todo_static_member_fn_call.carbon:[[@LINE+7]]:3: error: cannot implicitly convert from `Class(T)` to `Class(T)` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_todo_static_member_fn_call.carbon:[[@LINE+7]]:3: error: cannot implicitly convert value of type `Class(T)` to `Class(T)` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   return Class(T).Make();
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~~~~~
   // CHECK:STDERR: fail_todo_static_member_fn_call.carbon:[[@LINE+4]]:3: note: type `Class(T)` does not implement interface `Core.ImplicitAs(Class(T))` [MissingImplInMemberAccessNote]

toolchain/check/testdata/class/generic/stringify.carbon

@@ -16,7 +16,7 @@ class NoParams {}
 class EmptyParams() {}
 
 var v: NoParams;
-// CHECK:STDERR: fail_empty_params.carbon:[[@LINE+7]]:1: error: cannot implicitly convert from `NoParams` to `EmptyParams()` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_empty_params.carbon:[[@LINE+7]]:1: error: cannot implicitly convert value of type `NoParams` to `EmptyParams()` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var w: EmptyParams() = v;
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR: fail_empty_params.carbon:[[@LINE+4]]:1: note: type `NoParams` does not implement interface `Core.ImplicitAs(EmptyParams())` [MissingImplInMemberAccessNote]
@@ -37,7 +37,7 @@ class Outer(T:! type) {
 var v: Outer({}*);
 
 // TODO: It would be nice to include the `Outer({}*).` prefix in the name of `Inner`.
-// CHECK:STDERR: fail_nested.carbon:[[@LINE+7]]:1: error: cannot implicitly convert from `Outer({}*)` to `Inner({.a: i32}*)` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_nested.carbon:[[@LINE+7]]:1: error: cannot implicitly convert value of type `Outer({}*)` to `Inner({.a: i32}*)` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var w: Outer({}*).Inner({.a: i32}*) = v;
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR: fail_nested.carbon:[[@LINE+4]]:1: note: type `Outer({}*)` does not implement interface `Core.ImplicitAs(Inner({.a: i32}*))` [MissingImplInMemberAccessNote]
@@ -52,7 +52,7 @@ library "[[@TEST_NAME]]";
 
 class C(N:! i32) {}
 
-// CHECK:STDERR: fail_int_value.carbon:[[@LINE+7]]:1: error: cannot implicitly convert from `()` to `C(123)` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_int_value.carbon:[[@LINE+7]]:1: error: cannot implicitly convert value of type `()` to `C(123)` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var v: C(123) = ();
 // CHECK:STDERR: ^~~~~~~~~~~~~
 // CHECK:STDERR: fail_int_value.carbon:[[@LINE+4]]:1: note: type `()` does not implement interface `Core.ImplicitAs(C(123))` [MissingImplInMemberAccessNote]

toolchain/check/testdata/class/self.carbon

@@ -32,7 +32,7 @@ fn Class.G[addr self: Self*]() -> i32 {
 library "[[@TEST_NAME]]";
 
 class Class {
-  // CHECK:STDERR: fail_return_self_value.carbon:[[@LINE+7]]:25: error: cannot implicitly convert from `Class` to `type` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_return_self_value.carbon:[[@LINE+7]]:25: error: cannot implicitly convert value of type `Class` to `type` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   fn F[self: Self]() -> self;
   // CHECK:STDERR:                         ^~~~
   // CHECK:STDERR: fail_return_self_value.carbon:[[@LINE+4]]:25: note: type `Class` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/const/fail_collapse.carbon

@@ -13,7 +13,7 @@
 // CHECK:STDERR:         ^~~~~~~~~~~~~~~~~
 // CHECK:STDERR:
 fn G(p: const (const i32)**) -> i32** {
-  // CHECK:STDERR: fail_collapse.carbon:[[@LINE+7]]:3: error: cannot implicitly convert from `const i32**` to `i32**` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_collapse.carbon:[[@LINE+7]]:3: error: cannot implicitly convert value of type `const i32**` to `i32**` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   return p;
   // CHECK:STDERR:   ^~~~~~~~~
   // CHECK:STDERR: fail_collapse.carbon:[[@LINE+4]]:3: note: type `const i32**` does not implement interface `Core.ImplicitAs(i32**)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/deduce/array.carbon

@@ -58,7 +58,7 @@ fn F[T:! type](a: array(T, 2)) -> T { return a[0]; }
 fn G() -> C {
   // TODO: We succeed at deducing T here but fail to convert. Is this the right behavior?
   var a: array(C, 3) = ({}, {}, {});
-  // CHECK:STDERR: fail_bound_mismatch.carbon:[[@LINE+10]]:12: error: cannot implicitly convert from `[C; 3]` to `[C; 2]` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_bound_mismatch.carbon:[[@LINE+10]]:12: error: cannot implicitly convert value of type `[C; 3]` to `[C; 2]` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   return F(a);
   // CHECK:STDERR:            ^
   // CHECK:STDERR: fail_bound_mismatch.carbon:[[@LINE+7]]:12: note: type `[C; 3]` does not implement interface `Core.ImplicitAs([C; 2])` [MissingImplInMemberAccessNote]
@@ -83,7 +83,7 @@ fn F[N:! Core.IntLiteral()](a: array(C, N)) -> i32 { return N; }
 fn G() -> i32 {
   // TODO: We succeed at deducing N here but fail to convert. Is this the right behavior?
   var a: array(D, 3) = ({}, {}, {});
-  // CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+10]]:12: error: cannot implicitly convert from `[D; 3]` to `[C; 3]` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+10]]:12: error: cannot implicitly convert value of type `[D; 3]` to `[C; 3]` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   return F(a);
   // CHECK:STDERR:            ^
   // CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+7]]:12: note: type `[D; 3]` does not implement interface `Core.ImplicitAs([C; 3])` [MissingImplInMemberAccessNote]

toolchain/check/testdata/facet/no_prelude/combine.carbon

@@ -132,7 +132,7 @@ fn F() {
   // CHECK:STDERR:   (({} as C) as (C as (A & B))).((A & B).G)();
   // CHECK:STDERR:                  ^~~~~~~~~~~~
   // CHECK:STDERR:
-  // CHECK:STDERR: fail_todo_combine.carbon:[[@LINE+7]]:18: error: cannot convert from `type` to `A & B` with `as` [ExplicitAsConversionFailure]
+  // CHECK:STDERR: fail_todo_combine.carbon:[[@LINE+7]]:18: error: cannot convert value of type `type` to `A & B` with `as` [ExplicitAsConversionFailure]
   // CHECK:STDERR:   (({} as C) as (C as (A & B))).((A & B).G)();
   // CHECK:STDERR:                  ^~~~~~~~~~~~
   // CHECK:STDERR: fail_todo_combine.carbon:[[@LINE+4]]:18: note: type `type` does not implement interface `Core.As(A & B)` [MissingImplInMemberAccessNote]
@@ -145,7 +145,7 @@ fn F() {
   // CHECK:STDERR:   (({} as C) as (C as (A & B))).((B).G)();
   // CHECK:STDERR:                  ^~~~~~~~~~~~
   // CHECK:STDERR:
-  // CHECK:STDERR: fail_todo_combine.carbon:[[@LINE+7]]:18: error: cannot convert from `type` to `A & B` with `as` [ExplicitAsConversionFailure]
+  // CHECK:STDERR: fail_todo_combine.carbon:[[@LINE+7]]:18: error: cannot convert value of type `type` to `A & B` with `as` [ExplicitAsConversionFailure]
   // CHECK:STDERR:   (({} as C) as (C as (A & B))).((B).G)();
   // CHECK:STDERR:                  ^~~~~~~~~~~~
   // CHECK:STDERR: fail_todo_combine.carbon:[[@LINE+4]]:18: note: type `type` does not implement interface `Core.As(A & B)` [MissingImplInMemberAccessNote]
@@ -189,7 +189,7 @@ fn F() {
   // CHECK:STDERR: fn G[T:! A & B](t: T) {
   // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~
   // CHECK:STDERR:
-  // CHECK:STDERR: fail_todo_generic_combine.carbon:[[@LINE+10]]:3: error: cannot implicitly convert from `type` to `A & B` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_todo_generic_combine.carbon:[[@LINE+10]]:3: error: cannot implicitly convert value of type `type` to `A & B` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   G({} as C);
   // CHECK:STDERR:   ^~~~~~~~~~
   // CHECK:STDERR: fail_todo_generic_combine.carbon:[[@LINE+7]]:3: note: type `type` does not implement interface `Core.ImplicitAs(A & B)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/function/call/fail_param_type.carbon

@@ -11,7 +11,7 @@
 fn G(a: i32) {}
 
 fn F() {
-  // CHECK:STDERR: fail_param_type.carbon:[[@LINE+10]]:5: error: cannot implicitly convert from `f64` to `i32` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_param_type.carbon:[[@LINE+10]]:5: error: cannot implicitly convert value of type `f64` to `i32` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   G(1.0);
   // CHECK:STDERR:     ^~~
   // CHECK:STDERR: fail_param_type.carbon:[[@LINE+7]]:5: note: type `f64` does not implement interface `Core.ImplicitAs(i32)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/function/call/fail_return_type_mismatch.carbon

@@ -11,7 +11,7 @@
 fn Foo() -> f64 { return 1.0; }
 
 fn Run() {
-  // CHECK:STDERR: fail_return_type_mismatch.carbon:[[@LINE+7]]:3: error: cannot implicitly convert from `f64` to `i32` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_return_type_mismatch.carbon:[[@LINE+7]]:3: error: cannot implicitly convert value of type `f64` to `i32` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   var x: i32 = Foo();
   // CHECK:STDERR:   ^~~~~~~~~~
   // CHECK:STDERR: fail_return_type_mismatch.carbon:[[@LINE+4]]:3: note: type `f64` does not implement interface `Core.ImplicitAs(i32)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/impl/assoc_const_self.carbon

@@ -28,7 +28,7 @@ interface I {
   let V:! Self;
 }
 
-// CHECK:STDERR: fail_assoc_const_mismatch.carbon:[[@LINE+7]]:12: error: cannot implicitly convert from `Core.IntLiteral` to `{}` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_assoc_const_mismatch.carbon:[[@LINE+7]]:12: error: cannot implicitly convert value of type `Core.IntLiteral` to `{}` [ImplicitAsConversionFailure]
 // CHECK:STDERR: impl {} as I where .V = 0 {}
 // CHECK:STDERR:            ^~~~~~~~~~~~~~
 // CHECK:STDERR: fail_assoc_const_mismatch.carbon:[[@LINE+4]]:12: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs({})` [MissingImplInMemberAccessNote]
@@ -86,7 +86,7 @@ fn F(T:! I where {} impls Core.ImplicitAs(.Self) and .V = {});
 
 fn CallF() {
   // TODO: This call should eventually work.
-  // CHECK:STDERR: fail_todo_constrained_fn.carbon:[[@LINE+10]]:3: error: cannot implicitly convert from `{}` to `I where .(I.V) = {} and...` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_todo_constrained_fn.carbon:[[@LINE+10]]:3: error: cannot implicitly convert value of type `{}` to `I where .(I.V) = {} and...` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   F({});
   // CHECK:STDERR:   ^~~~~
   // CHECK:STDERR: fail_todo_constrained_fn.carbon:[[@LINE+7]]:3: note: type `{}` does not implement interface `Core.ImplicitAs(I where .(I.V) = {} and...)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/impl/fail_impl_bad_interface.carbon

@@ -12,7 +12,7 @@
 
 library "[[@TEST_NAME]]";
 
-// CHECK:STDERR: fail_impl_as_false.carbon:[[@LINE+7]]:13: error: cannot implicitly convert from `bool` to `type` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_impl_as_false.carbon:[[@LINE+7]]:13: error: cannot implicitly convert value of type `bool` to `type` [ImplicitAsConversionFailure]
 // CHECK:STDERR: impl i32 as false {}
 // CHECK:STDERR:             ^~~~~
 // CHECK:STDERR: fail_impl_as_false.carbon:[[@LINE+4]]:13: note: type `bool` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/impl/fail_todo_use_assoc_const.carbon

@@ -13,14 +13,14 @@ library "[[@TEST_NAME]]";
 
 interface J {
   let U:! type;
-  // CHECK:STDERR: fail_todo_associated_type_in_signature.carbon:[[@LINE+14]]:23: error: cannot implicitly convert from `<associated entity in J>` to `type` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_todo_associated_type_in_signature.carbon:[[@LINE+14]]:23: error: cannot implicitly convert value of type `<associated entity in J>` to `type` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   fn F[self: Self](u: U) -> U;
   // CHECK:STDERR:                       ^
   // CHECK:STDERR: fail_todo_associated_type_in_signature.carbon:[[@LINE+11]]:23: note: type `<associated entity in J>` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]
   // CHECK:STDERR:   fn F[self: Self](u: U) -> U;
   // CHECK:STDERR:                       ^
   // CHECK:STDERR:
-  // CHECK:STDERR: fail_todo_associated_type_in_signature.carbon:[[@LINE+7]]:29: error: cannot implicitly convert from `<associated entity in J>` to `type` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_todo_associated_type_in_signature.carbon:[[@LINE+7]]:29: error: cannot implicitly convert value of type `<associated entity in J>` to `type` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   fn F[self: Self](u: U) -> U;
   // CHECK:STDERR:                             ^
   // CHECK:STDERR: fail_todo_associated_type_in_signature.carbon:[[@LINE+4]]:29: note: type `<associated entity in J>` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]
@@ -53,7 +53,7 @@ interface M {
 
 impl () as M where .Z = {.b = {}} {
   fn G() -> {} {
-    // CHECK:STDERR: fail_todo_use_non-type_in_function.carbon:[[@LINE+7]]:13: error: cannot convert from `type` to `M` with `as` [ExplicitAsConversionFailure]
+    // CHECK:STDERR: fail_todo_use_non-type_in_function.carbon:[[@LINE+7]]:13: error: cannot convert value of type `type` to `M` with `as` [ExplicitAsConversionFailure]
     // CHECK:STDERR:     return (Self as M).Z.b;
     // CHECK:STDERR:             ^~~~~~~~~
     // CHECK:STDERR: fail_todo_use_non-type_in_function.carbon:[[@LINE+4]]:13: note: type `type` does not implement interface `Core.As(M)` [MissingImplInMemberAccessNote]
@@ -69,7 +69,7 @@ library "[[@TEST_NAME]]";
 
 interface I {
   let N:! i32;
-  // CHECK:STDERR: fail_todo_associated_int_in_array.carbon:[[@LINE+7]]:37: error: cannot implicitly convert from `<associated entity in I>` to `Core.IntLiteral` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_todo_associated_int_in_array.carbon:[[@LINE+7]]:37: error: cannot implicitly convert value of type `<associated entity in I>` to `Core.IntLiteral` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   fn F[self: Self]() -> array(bool, N);
   // CHECK:STDERR:                                     ^
   // CHECK:STDERR: fail_todo_associated_int_in_array.carbon:[[@LINE+4]]:37: note: type `<associated entity in I>` does not implement interface `Core.ImplicitAs(Core.IntLiteral)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/impl/no_prelude/impl_cycle.carbon

@@ -155,7 +155,7 @@ fn F() {
   // CHECK:STDERR: fn Compare[T:! type, U:! ComparableWith(T)](t: T, u: U) {}
   // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   // CHECK:STDERR:
-  // CHECK:STDERR: fail_impl_cycle_one_generic_param.carbon:[[@LINE+10]]:3: error: cannot implicitly convert from `type` to `ComparableWith(C)` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_impl_cycle_one_generic_param.carbon:[[@LINE+10]]:3: error: cannot implicitly convert value of type `type` to `ComparableWith(C)` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   Compare({} as C, {} as C);
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~~~~~~~
   // CHECK:STDERR: fail_impl_cycle_one_generic_param.carbon:[[@LINE+7]]:3: note: type `type` does not implement interface `Core.ImplicitAs(ComparableWith(C))` [MissingImplInMemberAccessNote]

toolchain/check/testdata/index/fail_array_non_int_indexing.carbon

@@ -9,7 +9,7 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/index/fail_array_non_int_indexing.carbon
 
 var a: array(i32, 1) = (12,);
-// CHECK:STDERR: fail_array_non_int_indexing.carbon:[[@LINE+7]]:16: error: cannot implicitly convert from `f64` to `i32` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_array_non_int_indexing.carbon:[[@LINE+7]]:16: error: cannot implicitly convert value of type `f64` to `i32` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var b: i32 = a[2.6];
 // CHECK:STDERR:                ^~~
 // CHECK:STDERR: fail_array_non_int_indexing.carbon:[[@LINE+4]]:16: note: type `f64` does not implement interface `Core.ImplicitAs(i32)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/interface/fail_assoc_const_bad_default.carbon

@@ -9,7 +9,7 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/fail_assoc_const_bad_default.carbon
 
 interface I {
-  // CHECK:STDERR: fail_assoc_const_bad_default.carbon:[[@LINE+7]]:3: error: cannot implicitly convert from `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_assoc_const_bad_default.carbon:[[@LINE+7]]:3: error: cannot implicitly convert value of type `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   let T:! type = 42;
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~
   // CHECK:STDERR: fail_assoc_const_bad_default.carbon:[[@LINE+4]]:3: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/let/compile_time_bindings.carbon

@@ -107,7 +107,7 @@ library "[[@TEST_NAME]]";
 
 interface I {
   let T:! type = i32;
-  // CHECK:STDERR: fail_return_in_interface.carbon:[[@LINE+7]]:13: error: cannot implicitly convert from `<associated entity in I>` to `type` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_return_in_interface.carbon:[[@LINE+7]]:13: error: cannot implicitly convert value of type `<associated entity in I>` to `type` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   fn F() -> T;
   // CHECK:STDERR:             ^
   // CHECK:STDERR: fail_return_in_interface.carbon:[[@LINE+4]]:13: note: type `<associated entity in I>` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/let/fail_generic.carbon

@@ -11,7 +11,7 @@
 // TODO: Should this be valid?
 fn F(a: i32) -> i32 {
   let T:! type = i32;
-  // CHECK:STDERR: fail_generic.carbon:[[@LINE+7]]:14: error: cannot implicitly convert from `Core.IntLiteral` to `T` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_generic.carbon:[[@LINE+7]]:14: error: cannot implicitly convert value of type `Core.IntLiteral` to `T` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   let x: T = 5;
   // CHECK:STDERR:              ^
   // CHECK:STDERR: fail_generic.carbon:[[@LINE+4]]:14: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(T)` [MissingImplInMemberAccessNote]
@@ -19,7 +19,7 @@ fn F(a: i32) -> i32 {
   // CHECK:STDERR:              ^
   // CHECK:STDERR:
   let x: T = 5;
-  // CHECK:STDERR: fail_generic.carbon:[[@LINE+7]]:3: error: cannot implicitly convert from `T` to `i32` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_generic.carbon:[[@LINE+7]]:3: error: cannot implicitly convert value of type `T` to `i32` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   return x;
   // CHECK:STDERR:   ^~~~~~~~~
   // CHECK:STDERR: fail_generic.carbon:[[@LINE+4]]:3: note: type `T` does not implement interface `Core.ImplicitAs(i32)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/operators/builtin/fail_type_mismatch.carbon

@@ -9,7 +9,7 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/operators/builtin/fail_type_mismatch.carbon
 
 fn Main() {
-  // CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+7]]:17: error: cannot implicitly convert from `Core.IntLiteral` to `bool` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+7]]:17: error: cannot implicitly convert value of type `Core.IntLiteral` to `bool` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   var x: bool = not 12;
   // CHECK:STDERR:                 ^~~~~~
   // CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+4]]:17: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(bool)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/operators/builtin/fail_type_mismatch_assignment.carbon

@@ -10,7 +10,7 @@
 
 fn Main() {
   var a: i32 = 3;
-  // CHECK:STDERR: fail_type_mismatch_assignment.carbon:[[@LINE+7]]:3: error: cannot implicitly convert from `f64` to `i32` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_type_mismatch_assignment.carbon:[[@LINE+7]]:3: error: cannot implicitly convert value of type `f64` to `i32` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   a = 5.6;
   // CHECK:STDERR:   ^~~~~~~
   // CHECK:STDERR: fail_type_mismatch_assignment.carbon:[[@LINE+4]]:3: note: type `f64` does not implement interface `Core.ImplicitAs(i32)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/operators/overloaded/eq.carbon

@@ -62,7 +62,7 @@ impl C as Core.Eq {
 }
 
 fn TestRhsBad(a: C, b: D) -> bool {
-  // CHECK:STDERR: fail_no_impl_for_args.carbon:[[@LINE+10]]:15: error: cannot implicitly convert from `D` to `C` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_no_impl_for_args.carbon:[[@LINE+10]]:15: error: cannot implicitly convert value of type `D` to `C` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   return a == b;
   // CHECK:STDERR:               ^
   // CHECK:STDERR: fail_no_impl_for_args.carbon:[[@LINE+7]]:15: note: type `D` does not implement interface `Core.ImplicitAs(C)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/operators/overloaded/fail_no_impl_for_arg.carbon

@@ -21,7 +21,7 @@ impl C as Core.AddAssign {
 }
 
 fn Test(a: C, b: D) -> C {
-  // CHECK:STDERR: fail_no_impl_for_arg.carbon:[[@LINE+10]]:14: error: cannot implicitly convert from `D` to `C` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_no_impl_for_arg.carbon:[[@LINE+10]]:14: error: cannot implicitly convert value of type `D` to `C` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   return a + b;
   // CHECK:STDERR:              ^
   // CHECK:STDERR: fail_no_impl_for_arg.carbon:[[@LINE+7]]:14: note: type `D` does not implement interface `Core.ImplicitAs(C)` [MissingImplInMemberAccessNote]
@@ -36,7 +36,7 @@ fn Test(a: C, b: D) -> C {
 
 fn TestAssign(b: D) {
   var a: C = {};
-  // CHECK:STDERR: fail_no_impl_for_arg.carbon:[[@LINE+10]]:8: error: cannot implicitly convert from `D` to `C` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_no_impl_for_arg.carbon:[[@LINE+10]]:8: error: cannot implicitly convert value of type `D` to `C` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   a += b;
   // CHECK:STDERR:        ^
   // CHECK:STDERR: fail_no_impl_for_arg.carbon:[[@LINE+7]]:8: note: type `D` does not implement interface `Core.ImplicitAs(C)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/operators/overloaded/index.carbon

@@ -54,7 +54,7 @@ impl C as Core.IndexWith(SubscriptType, ElementType) {
 }
 
 let c: C = {};
-// CHECK:STDERR: fail_invalid_subscript_type.carbon:[[@LINE+7]]:22: error: cannot implicitly convert from `Core.IntLiteral` to `SubscriptType` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_invalid_subscript_type.carbon:[[@LINE+7]]:22: error: cannot implicitly convert value of type `Core.IntLiteral` to `SubscriptType` [ImplicitAsConversionFailure]
 // CHECK:STDERR: let x: ElementType = c[0];
 // CHECK:STDERR:                      ^~~~
 // CHECK:STDERR: fail_invalid_subscript_type.carbon:[[@LINE+4]]:22: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(SubscriptType)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/pointer/fail_type_mismatch.carbon

@@ -9,7 +9,7 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/pointer/fail_type_mismatch.carbon
 
 fn ConstMismatch(p: const {}*) -> const ({}*) {
-  // CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+7]]:3: error: cannot implicitly convert from `const {}*` to `const ({}*)` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+7]]:3: error: cannot implicitly convert value of type `const {}*` to `const ({}*)` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   return p;
   // CHECK:STDERR:   ^~~~~~~~~
   // CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+4]]:3: note: type `const {}*` does not implement interface `Core.ImplicitAs(const ({}*))` [MissingImplInMemberAccessNote]

toolchain/check/testdata/return/fail_type_mismatch.carbon

@@ -9,7 +9,7 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/return/fail_type_mismatch.carbon
 
 fn Main() -> i32 {
-  // CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+7]]:3: error: cannot implicitly convert from `f64` to `i32` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+7]]:3: error: cannot implicitly convert value of type `f64` to `i32` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   return 1.0;
   // CHECK:STDERR:   ^~~~~~~~~~~
   // CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+4]]:3: note: type `f64` does not implement interface `Core.ImplicitAs(i32)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/struct/fail_type_assign.carbon

@@ -8,7 +8,7 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/struct/fail_type_assign.carbon
 
-// CHECK:STDERR: fail_type_assign.carbon:[[@LINE+7]]:1: error: cannot implicitly convert from `type` to `{.a: i32}` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_type_assign.carbon:[[@LINE+7]]:1: error: cannot implicitly convert value of type `type` to `{.a: i32}` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var x: {.a: i32} = {.a: i32};
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~
 // CHECK:STDERR: fail_type_assign.carbon:[[@LINE+4]]:1: note: type `type` does not implement interface `Core.ImplicitAs({.a: i32})` [MissingImplInMemberAccessNote]

toolchain/check/testdata/struct/fail_value_as_type.carbon

@@ -8,7 +8,7 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/struct/fail_value_as_type.carbon
 
-// CHECK:STDERR: fail_value_as_type.carbon:[[@LINE+7]]:8: error: cannot implicitly convert from `{.a: Core.IntLiteral}` to `type` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_value_as_type.carbon:[[@LINE+7]]:8: error: cannot implicitly convert value of type `{.a: Core.IntLiteral}` to `type` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var x: {.a = 1};
 // CHECK:STDERR:        ^~~~~~~~
 // CHECK:STDERR: fail_value_as_type.carbon:[[@LINE+4]]:8: note: type `{.a: Core.IntLiteral}` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/struct/import.carbon

@@ -43,7 +43,7 @@ var c_bad: C({.c = 1, .d = 2}) = F();
 // --- fail_bad_value.impl.carbon
 
 impl package Implicit;
-// CHECK:STDERR: fail_bad_value.impl.carbon:[[@LINE+7]]:1: error: cannot implicitly convert from `C({.a = 1, .b = 2})` to `C({.a = 3, .b = 4})` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_bad_value.impl.carbon:[[@LINE+7]]:1: error: cannot implicitly convert value of type `C({.a = 1, .b = 2})` to `C({.a = 3, .b = 4})` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var c_bad: C({.a = 3, .b = 4}) = F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR: fail_bad_value.impl.carbon:[[@LINE+4]]:1: note: type `C({.a = 1, .b = 2})` does not implement interface `Core.ImplicitAs(C({.a = 3, .b = 4}))` [MissingImplInMemberAccessNote]

toolchain/check/testdata/tuple/access/fail_non_int_indexing.carbon

@@ -9,7 +9,7 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/tuple/access/fail_non_int_indexing.carbon
 
 var a: (i32, i32) = (12, 6);
-// CHECK:STDERR: fail_non_int_indexing.carbon:[[@LINE+7]]:17: error: cannot implicitly convert from `f64` to `Core.IntLiteral` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_non_int_indexing.carbon:[[@LINE+7]]:17: error: cannot implicitly convert value of type `f64` to `Core.IntLiteral` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var b: i32 = a.(2.6);
 // CHECK:STDERR:                 ^~~
 // CHECK:STDERR: fail_non_int_indexing.carbon:[[@LINE+4]]:17: note: type `f64` does not implement interface `Core.ImplicitAs(Core.IntLiteral)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/tuple/fail_element_type_mismatch.carbon

@@ -8,7 +8,7 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/tuple/fail_element_type_mismatch.carbon
 
-// CHECK:STDERR: fail_element_type_mismatch.carbon:[[@LINE+7]]:21: error: cannot implicitly convert from `f64` to `i32` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_element_type_mismatch.carbon:[[@LINE+7]]:21: error: cannot implicitly convert value of type `f64` to `i32` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var x: (i32, i32) = (2, 65.89);
 // CHECK:STDERR:                     ^~~~~~~~~~
 // CHECK:STDERR: fail_element_type_mismatch.carbon:[[@LINE+4]]:21: note: type `f64` does not implement interface `Core.ImplicitAs(i32)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/tuple/fail_type_assign.carbon

@@ -8,7 +8,7 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/tuple/fail_type_assign.carbon
 
-// CHECK:STDERR: fail_type_assign.carbon:[[@LINE+7]]:18: error: cannot implicitly convert from `type` to `i32` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_type_assign.carbon:[[@LINE+7]]:18: error: cannot implicitly convert value of type `type` to `i32` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var x: (i32, ) = (i32, );
 // CHECK:STDERR:                  ^~~~~~~
 // CHECK:STDERR: fail_type_assign.carbon:[[@LINE+4]]:18: note: type `type` does not implement interface `Core.ImplicitAs(i32)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/tuple/fail_value_as_type.carbon

@@ -8,7 +8,7 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/tuple/fail_value_as_type.carbon
 
-// CHECK:STDERR: fail_value_as_type.carbon:[[@LINE+7]]:8: error: cannot implicitly convert from `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_value_as_type.carbon:[[@LINE+7]]:8: error: cannot implicitly convert value of type `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var x: (1, );
 // CHECK:STDERR:        ^~~~~
 // CHECK:STDERR: fail_value_as_type.carbon:[[@LINE+4]]:8: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/tuple/import.carbon

@@ -45,7 +45,7 @@ var c_bad: C((1, 2, 3)) = F();
 
 impl package Implicit;
 
-// CHECK:STDERR: fail_bad_value.impl.carbon:[[@LINE+7]]:1: error: cannot implicitly convert from `C((1, 2))` to `C((3, 4))` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_bad_value.impl.carbon:[[@LINE+7]]:1: error: cannot implicitly convert value of type `C((1, 2))` to `C((3, 4))` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var c_bad: C((3, 4)) = F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR: fail_bad_value.impl.carbon:[[@LINE+4]]:1: note: type `C((1, 2))` does not implement interface `Core.ImplicitAs(C((3, 4)))` [MissingImplInMemberAccessNote]

toolchain/check/testdata/var/fail_storage_is_literal.carbon

@@ -9,7 +9,7 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/var/fail_storage_is_literal.carbon
 
 fn Main() {
-  // CHECK:STDERR: fail_storage_is_literal.carbon:[[@LINE+7]]:10: error: cannot implicitly convert from `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_storage_is_literal.carbon:[[@LINE+7]]:10: error: cannot implicitly convert value of type `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   var x: 1 = 1;
   // CHECK:STDERR:          ^
   // CHECK:STDERR: fail_storage_is_literal.carbon:[[@LINE+4]]:10: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/where_expr/constraints.carbon

@@ -42,7 +42,7 @@ fn AssociatedTypeImpls(W:! K where .Associated impls M);
 
 library "[[@TEST_NAME]]";
 
-// CHECK:STDERR: fail_left_of_impls_non_type.carbon:[[@LINE+7]]:32: error: cannot implicitly convert from `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_left_of_impls_non_type.carbon:[[@LINE+7]]:32: error: cannot implicitly convert value of type `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
 // CHECK:STDERR: fn NonTypeImpls(U:! type where 7 impls type);
 // CHECK:STDERR:                                ^
 // CHECK:STDERR: fail_left_of_impls_non_type.carbon:[[@LINE+4]]:32: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]
@@ -55,7 +55,7 @@ fn NonTypeImpls(U:! type where 7 impls type);
 
 library "[[@TEST_NAME]]";
 
-// CHECK:STDERR: fail_right_of_impls_non_type.carbon:[[@LINE+7]]:44: error: cannot implicitly convert from `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_right_of_impls_non_type.carbon:[[@LINE+7]]:44: error: cannot implicitly convert value of type `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
 // CHECK:STDERR: fn ImplsNonType(U:! type where .Self impls 7);
 // CHECK:STDERR:                                            ^
 // CHECK:STDERR: fail_right_of_impls_non_type.carbon:[[@LINE+4]]:44: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]
@@ -86,7 +86,7 @@ impl C as J {}
 
 // TODO: Should report that `C` does not meet the constraint.
 fn DoesNotImplI() {
-  // CHECK:STDERR: fail_todo_enforce_constraint.carbon:[[@LINE+11]]:3: error: cannot implicitly convert from `type` to `J where...` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_todo_enforce_constraint.carbon:[[@LINE+11]]:3: error: cannot implicitly convert value of type `type` to `J where...` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   Impls(C);
   // CHECK:STDERR:   ^~~~~~~~
   // CHECK:STDERR: fail_todo_enforce_constraint.carbon:[[@LINE+8]]:3: note: type `type` does not implement interface `Core.ImplicitAs(J where...)` [MissingImplInMemberAccessNote]
@@ -104,7 +104,7 @@ fn EmptyStruct(Y:! J where .Self == {});
 
 // TODO: Should report that `C` does not meeet the constraint.
 fn NotEmptyStruct() {
-  // CHECK:STDERR: fail_todo_enforce_constraint.carbon:[[@LINE+10]]:3: error: cannot implicitly convert from `type` to `J where...` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_todo_enforce_constraint.carbon:[[@LINE+10]]:3: error: cannot implicitly convert value of type `type` to `J where...` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   EmptyStruct(C);
   // CHECK:STDERR:   ^~~~~~~~~~~~~~
   // CHECK:STDERR: fail_todo_enforce_constraint.carbon:[[@LINE+7]]:3: note: type `type` does not implement interface `Core.ImplicitAs(J where...)` [MissingImplInMemberAccessNote]

toolchain/check/testdata/where_expr/equal_rewrite.carbon

@@ -73,7 +73,7 @@ interface O {
 fn WithInteger(Q:! O where .P = i32) {}
 
 fn WithBool(R:! O where .P = bool) {
-  // CHECK:STDERR: fail_rewrites_mismatch_right.carbon:[[@LINE+10]]:3: error: cannot implicitly convert from `O where .(O.P) = bool` to `O where .(O.P) = i32` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_rewrites_mismatch_right.carbon:[[@LINE+10]]:3: error: cannot implicitly convert value of type `O where .(O.P) = bool` to `O where .(O.P) = i32` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   WithInteger(R);
   // CHECK:STDERR:   ^~~~~~~~~~~~~~
   // CHECK:STDERR: fail_rewrites_mismatch_right.carbon:[[@LINE+7]]:3: note: type `O where .(O.P) = bool` does not implement interface `Core.ImplicitAs(O where .(O.P) = i32)` [MissingImplInMemberAccessNote]
@@ -98,7 +98,7 @@ interface S {
 fn WithT(V:! S where .T = ()) {}
 
 fn WithU(W:! S where .U = ()) {
-  // CHECK:STDERR: fail_rewrites_mismatch_left.carbon:[[@LINE+10]]:3: error: cannot implicitly convert from `S where .(S.U) = ()` to `S where .(S.T) = ()` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_rewrites_mismatch_left.carbon:[[@LINE+10]]:3: error: cannot implicitly convert value of type `S where .(S.U) = ()` to `S where .(S.T) = ()` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   WithT(W);
   // CHECK:STDERR:   ^~~~~~~~
   // CHECK:STDERR: fail_rewrites_mismatch_left.carbon:[[@LINE+7]]:3: note: type `S where .(S.U) = ()` does not implement interface `Core.ImplicitAs(S where .(S.T) = ())` [MissingImplInMemberAccessNote]
@@ -119,7 +119,7 @@ import library "equal_constraint";
 import library "nested_rewrites";
 
 fn Calls() {
-  // CHECK:STDERR: fail_import_rewrites.carbon:[[@LINE+11]]:3: error: cannot implicitly convert from `type` to `N where .(N.P) = {}` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_import_rewrites.carbon:[[@LINE+11]]:3: error: cannot implicitly convert value of type `type` to `N where .(N.P) = {}` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   Equal(bool);
   // CHECK:STDERR:   ^~~~~~~~~~~
   // CHECK:STDERR: fail_import_rewrites.carbon:[[@LINE+8]]:3: note: type `type` does not implement interface `Core.ImplicitAs(N where .(N.P) = {})` [MissingImplInMemberAccessNote]
@@ -132,7 +132,7 @@ fn Calls() {
   // CHECK:STDERR:
   Equal(bool);
 
-  // CHECK:STDERR: fail_import_rewrites.carbon:[[@LINE+11]]:3: error: cannot implicitly convert from `type` to `A where .(A.C) = () and .(A.B) = bool` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_import_rewrites.carbon:[[@LINE+11]]:3: error: cannot implicitly convert value of type `type` to `A where .(A.C) = () and .(A.B) = bool` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   NestedRewrite(i32);
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~
   // CHECK:STDERR: fail_import_rewrites.carbon:[[@LINE+8]]:3: note: type `type` does not implement interface `Core.ImplicitAs(A where .(A.C) = () and .(A.B) = bool)` [MissingImplInMemberAccessNote]
@@ -155,7 +155,7 @@ interface I {
 }
 
 // `2` can't be converted to the type of `I.Member`
-// CHECK:STDERR: fail_check_rewrite_constraints.carbon:[[@LINE+7]]:46: error: cannot implicitly convert from `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_check_rewrite_constraints.carbon:[[@LINE+7]]:46: error: cannot implicitly convert value of type `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
 // CHECK:STDERR: fn RewriteTypeMismatch(X:! I where .Member = 2);
 // CHECK:STDERR:                                              ^
 // CHECK:STDERR: fail_check_rewrite_constraints.carbon:[[@LINE+4]]:46: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]
@@ -176,7 +176,7 @@ impl D as A {}
 // CHECK:STDERR: let B: type where .Self impls A = D;
 // CHECK:STDERR:                                   ^
 // CHECK:STDERR:
-// CHECK:STDERR: fail_todo_let.carbon:[[@LINE+7]]:35: error: cannot implicitly convert from `type` to `type where...` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_todo_let.carbon:[[@LINE+7]]:35: error: cannot implicitly convert value of type `type` to `type where...` [ImplicitAsConversionFailure]
 // CHECK:STDERR: let B: type where .Self impls A = D;
 // CHECK:STDERR:                                   ^
 // CHECK:STDERR: fail_todo_let.carbon:[[@LINE+4]]:35: note: type `type` does not implement interface `Core.ImplicitAs(type where...)` [MissingImplInMemberAccessNote]
@@ -196,7 +196,7 @@ interface E {
 // Testing how these types get stringified in error messages.
 
 // TODO: This should be a compile-time binding, once that is supported.
-// CHECK:STDERR: fail_type_does_not_implement_where.carbon:[[@LINE+7]]:42: error: cannot implicitly convert from `type` to `E where .(E.G) = () and .(E.F) = bool` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_type_does_not_implement_where.carbon:[[@LINE+7]]:42: error: cannot implicitly convert value of type `type` to `E where .(E.G) = () and .(E.F) = bool` [ImplicitAsConversionFailure]
 // CHECK:STDERR: let H: (E where .F = bool and .G = ()) = f64;
 // CHECK:STDERR:                                          ^~~
 // CHECK:STDERR: fail_type_does_not_implement_where.carbon:[[@LINE+4]]:42: note: type `type` does not implement interface `Core.ImplicitAs(E where .(E.G) = () and .(E.F) = bool)` [MissingImplInMemberAccessNote]
@@ -205,7 +205,7 @@ interface E {
 // CHECK:STDERR:
 let H: (E where .F = bool and .G = ()) = f64;
 
-// CHECK:STDERR: fail_type_does_not_implement_where.carbon:[[@LINE+7]]:45: error: cannot implicitly convert from `type` to `E where .(E.G) = i32 and .(E.F) = {}` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_type_does_not_implement_where.carbon:[[@LINE+7]]:45: error: cannot implicitly convert value of type `type` to `E where .(E.G) = i32 and .(E.F) = {}` [ImplicitAsConversionFailure]
 // CHECK:STDERR: let J: ((E where .F = {}) where .G = i32) = bool;
 // CHECK:STDERR:                                             ^~~~
 // CHECK:STDERR: fail_type_does_not_implement_where.carbon:[[@LINE+4]]:45: note: type `type` does not implement interface `Core.ImplicitAs(E where .(E.G) = i32 and .(E.F) = {})` [MissingImplInMemberAccessNote]
@@ -214,7 +214,7 @@ let H: (E where .F = bool and .G = ()) = f64;
 // CHECK:STDERR:
 let J: ((E where .F = {}) where .G = i32) = bool;
 
-// CHECK:STDERR: fail_type_does_not_implement_where.carbon:[[@LINE+7]]:33: error: cannot implicitly convert from `type` to `E where .(E.F) = .(E.G)` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_type_does_not_implement_where.carbon:[[@LINE+7]]:33: error: cannot implicitly convert value of type `type` to `E where .(E.F) = .(E.G)` [ImplicitAsConversionFailure]
 // CHECK:STDERR: let K: (E where .F = .Self.G) = bool;
 // CHECK:STDERR:                                 ^~~~
 // CHECK:STDERR: fail_type_does_not_implement_where.carbon:[[@LINE+4]]:33: note: type `type` does not implement interface `Core.ImplicitAs(E where .(E.F) = .(E.G))` [MissingImplInMemberAccessNote]

toolchain/check/testdata/while/fail_bad_condition.carbon

@@ -9,7 +9,7 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/while/fail_bad_condition.carbon
 
 fn While() {
-  // CHECK:STDERR: fail_bad_condition.carbon:[[@LINE+7]]:9: error: cannot implicitly convert from `String` to `bool` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_bad_condition.carbon:[[@LINE+7]]:9: error: cannot implicitly convert value of type `String` to `bool` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   while ("Hello") {}
   // CHECK:STDERR:         ^~~~~~~~~
   // CHECK:STDERR: fail_bad_condition.carbon:[[@LINE+4]]:9: note: type `String` does not implement interface `Core.ImplicitAs(bool)` [MissingImplInMemberAccessNote]