fix: allow performing bitwise NOT on unsigned integers

compiler/noirc_frontend/src/hir/type_check/stmt.rs

@@ -8,6 +8,7 @@ use crate::hir_def::stmt::{
 };
 use crate::hir_def::types::Type;
 use crate::node_interner::{DefinitionId, ExprId, StmtId};
+use crate::UnaryOp;
 
 use super::errors::{Source, TypeCheckError};
 use super::TypeChecker;
@@ -361,9 +362,15 @@ impl<'interner> TypeChecker<'interner> {
                     };
                 };
             }
-            HirExpression::Prefix(_) => self
-                .errors
-                .push(TypeCheckError::InvalidUnaryOp { kind: annotated_type.to_string(), span }),
+            HirExpression::Prefix(expr) => {
+                self.lint_overflowing_uint(&expr.rhs, annotated_type);
+                if matches!(expr.operator, UnaryOp::Minus) {
+                    self.errors.push(TypeCheckError::InvalidUnaryOp {
+                        kind: "annotated_type".to_string(),
+                        span,
+                    });
+                }
+            }
             HirExpression::Infix(expr) => {
                 self.lint_overflowing_uint(&expr.lhs, annotated_type);
                 self.lint_overflowing_uint(&expr.rhs, annotated_type);

test_programs/execution_success/bit_not/Nargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "bit_not"
+type = "bin"
+authors = [""]
+compiler_version = ">=0.23.0"
+
+[dependencies]

test_programs/execution_success/bit_not/Prover.toml

@@ -0,0 +1 @@
+x = 4

test_programs/execution_success/bit_not/src/main.nr

@@ -0,0 +1,8 @@
+fn main(four_as_u32: u32) {
+    let four_as_u8: u8 = 4;
+    let not_four_as_u8: u8 = !four_as_u8;
+    assert_eq(not_four_as_u8, 251);
+
+    let not_four_as_u32: u32 = !four_as_u32;
+    assert_eq(not_four_as_u32, 4294967291);
+}