5 #![allow(blacklisted_name)]
7 /// Test that we lint if we use a binding with a single leading underscore
8 fn prefix_underscore(_foo: u32) -> u32 {
9 _foo + 1 //~ ERROR used binding which is prefixed with an underscore
12 /// Test that we lint even if the use is within a macro expansion
13 fn in_macro(_foo: u32) {
14 println!("{}", _foo); //~ ERROR used binding which is prefixed with an underscore
17 // Struct for testing use of fields prefixed with an underscore
18 struct StructFieldTest {
19 _underscore_field: u32,
22 /// Test that we lint the use of a struct field which is prefixed with an underscore
23 fn in_struct_field() {
24 let mut s = StructFieldTest { _underscore_field: 0 };
25 s._underscore_field += 1; //~ Error used binding which is prefixed with an underscore
28 /// Test that we do not lint if the underscore is not a prefix
29 fn non_prefix_underscore(some_foo: u32) -> u32 {
33 /// Test that we do not lint if we do not use the binding (simple case)
34 fn unused_underscore_simple(_foo: u32) -> u32 {
38 /// Test that we do not lint if we do not use the binding (complex case). This checks for
39 /// compatibility with the built-in `unused_variables` lint.
40 fn unused_underscore_complex(mut _foo: u32) -> u32 {
46 ///Test that we do not lint for multiple underscores
47 fn multiple_underscores(__foo: u32) -> u32 {
51 // Non-variable bindings with preceding underscore
59 /// Test that we do not lint for non-variable bindings
63 let _e = match _EnumTest::_Value(_StructTest) {
64 _EnumTest::_Empty => 0,
65 _EnumTest::_Value(_st) => 1,
73 // tests of unused_underscore lint
74 let _ = prefix_underscore(foo);
77 // possible false positives
78 let _ = non_prefix_underscore(foo);
79 let _ = unused_underscore_simple(foo);
80 let _ = unused_underscore_complex(foo);
81 let _ = multiple_underscores(foo);