5 #![allow(blacklisted_name)]
6 #![deny(used_underscore_binding)]
8 macro_rules! test_macro {
15 /// Test that we lint if we use a binding with a single leading underscore
16 fn prefix_underscore(_foo: u32) -> u32 {
20 /// Test that we lint if we use a `_`-variable defined outside within a macro expansion
21 fn in_macro(_foo: u32) {
24 assert_eq!(_foo, _foo);
31 // Struct for testing use of fields prefixed with an underscore
32 struct StructFieldTest {
33 _underscore_field: u32,
36 /// Test that we lint the use of a struct field which is prefixed with an underscore
37 fn in_struct_field() {
38 let mut s = StructFieldTest { _underscore_field: 0 };
39 s._underscore_field += 1;
42 /// Test that we do not lint if the underscore is not a prefix
43 fn non_prefix_underscore(some_foo: u32) -> u32 {
47 /// Test that we do not lint if we do not use the binding (simple case)
48 fn unused_underscore_simple(_foo: u32) -> u32 {
52 /// Test that we do not lint if we do not use the binding (complex case). This checks for
53 /// compatibility with the built-in `unused_variables` lint.
54 fn unused_underscore_complex(mut _foo: u32) -> u32 {
60 ///Test that we do not lint for multiple underscores
61 fn multiple_underscores(__foo: u32) -> u32 {
65 // Non-variable bindings with preceding underscore
73 /// Test that we do not lint for non-variable bindings
77 let _e = match _EnumTest::_Value(_StructTest) {
78 _EnumTest::_Empty => 0,
79 _EnumTest::_Value(_st) => 1,
87 // tests of unused_underscore lint
88 let _ = prefix_underscore(foo);
91 // possible false positives
92 let _ = non_prefix_underscore(foo);
93 let _ = unused_underscore_simple(foo);
94 let _ = unused_underscore_complex(foo);
95 let _ = multiple_underscores(foo);