forbid generic params in complex consts

src/test/ui/const-generics/min_const_generics/complex-expression.rs

@@ -0,0 +1,37 @@
+#![feature(min_const_generics)]
+
+fn test<const N: usize>() {}
+
+fn ok<const M: usize>() -> [u8; M] {
+    [0; { M }]
+}
+
+struct Break0<const N: usize>([u8; { N + 1 }]);
+//~^ ERROR generic parameters must not be used inside of non trivial constant values
+
+struct Break1<const N: usize>([u8; { { N } }]);
+//~^ ERROR generic parameters must not be used inside of non trivial constant values
+
+fn break2<const N: usize>() {
+    let _: [u8; N + 1];
+    //~^ ERROR generic parameters must not be used inside of non trivial constant values
+}
+
+fn break3<const N: usize>() {
+    let _ = [0; N + 1];
+    //~^ ERROR generic parameters must not be used inside of non trivial constant values
+}
+
+trait Foo {
+    const ASSOC: usize;
+}
+
+impl<const N: usize> Foo for [u8; N] {
+    const ASSOC: usize = N + 1;
+    //~^ ERROR generic parameters must not be used inside of non trivial constant values
+    // FIXME(min_const_generics): We probably have to allow this as we can
+    // already allow referencing type parameters here on stable.
+}
+
+
+fn main() {}