1 files changed, 49 insertions, 0 deletions
diff --git a/compiler/rustc_error_codes/src/error_codes/E0070.md b/compiler/rustc_error_codes/src/error_codes/E0070.md
new file mode 100644
index 000000000..97522af3d
--- /dev/null
+++ b/compiler/rustc_error_codes/src/error_codes/E0070.md
@@ -0,0 +1,49 @@
+An assignment operator was used on a non-place expression.
+
+Erroneous code examples:
+
+```compile_fail,E0070
+struct SomeStruct {
+    x: i32,
+    y: i32,
+}
+
+const SOME_CONST: i32 = 12;
+
+fn some_other_func() {}
+
+fn some_function() {
+    SOME_CONST = 14; // error: a constant value cannot be changed!
+    1 = 3; // error: 1 isn't a valid place!
+    some_other_func() = 4; // error: we cannot assign value to a function!
+    SomeStruct::x = 12; // error: SomeStruct a structure name but it is used
+                        //        like a variable!
+}
+```
+
+The left-hand side of an assignment operator must be a place expression. A
+place expression represents a memory location and can be a variable (with
+optional namespacing), a dereference, an indexing expression or a field
+reference.
+
+More details can be found in the [Expressions] section of the Reference.
+
+[Expressions]: https://doc.rust-lang.org/reference/expressions.html#places-rvalues-and-temporaries
+
+And now let's give working examples:
+
+```
+struct SomeStruct {
+    x: i32,
+    y: i32,
+}
+let mut s = SomeStruct { x: 0, y: 0 };
+
+s.x = 3; // that's good !
+
+// ...
+
+fn some_func(x: &mut i32) {
+    *x = 12; // that's good !
+}
+```