diff options
Diffstat (limited to 'src/tools/clippy/tests/ui/unnecessary_struct_initialization.rs')
-rw-r--r-- | src/tools/clippy/tests/ui/unnecessary_struct_initialization.rs | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/src/tools/clippy/tests/ui/unnecessary_struct_initialization.rs b/src/tools/clippy/tests/ui/unnecessary_struct_initialization.rs new file mode 100644 index 000000000..63b11c626 --- /dev/null +++ b/src/tools/clippy/tests/ui/unnecessary_struct_initialization.rs @@ -0,0 +1,77 @@ +// run-rustfix + +#![allow(unused)] +#![warn(clippy::unnecessary_struct_initialization)] + +struct S { + f: String, +} + +#[derive(Clone, Copy)] +struct T { + f: u32, +} + +struct U { + f: u32, +} + +impl Clone for U { + fn clone(&self) -> Self { + // Do not lint: `Self` does not implement `Copy` + Self { ..*self } + } +} + +#[derive(Copy)] +struct V { + f: u32, +} + +impl Clone for V { + fn clone(&self) -> Self { + // Lint: `Self` implements `Copy` + Self { ..*self } + } +} + +fn main() { + // Should lint: `a` would be consumed anyway + let a = S { f: String::from("foo") }; + let mut b = S { ..a }; + + // Should lint: `b` would be consumed, and is mutable + let c = &mut S { ..b }; + + // Should not lint as `d` is not mutable + let d = S { f: String::from("foo") }; + let e = &mut S { ..d }; + + // Should lint as `f` would be consumed anyway + let f = S { f: String::from("foo") }; + let g = &S { ..f }; + + // Should lint: the result of an expression is mutable + let h = &mut S { + ..*Box::new(S { f: String::from("foo") }) + }; + + // Should not lint: `m` would be both alive and borrowed + let m = T { f: 17 }; + let n = &T { ..m }; + + // Should not lint: `m` should not be modified + let o = &mut T { ..m }; + o.f = 32; + assert_eq!(m.f, 17); + + // Should not lint: `m` should not be modified + let o = &mut T { ..m } as *mut T; + unsafe { &mut *o }.f = 32; + assert_eq!(m.f, 17); + + // Should lint: the result of an expression is mutable and temporary + let p = &mut T { + ..*Box::new(T { f: 5 }) + }; +} |