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|
#![warn(clippy::const_is_empty)]
#![allow(clippy::needless_late_init, unused_must_use)]
fn test_literal() {
if "".is_empty() {
//~^ const_is_empty
}
if "foobar".is_empty() {
//~^ const_is_empty
}
}
fn test_byte_literal() {
if b"".is_empty() {
//~^ const_is_empty
}
if b"foobar".is_empty() {
//~^ const_is_empty
}
}
fn test_no_mut() {
let mut empty = "";
if empty.is_empty() {
// No lint because it is mutable
}
}
fn test_propagated() {
let empty = "";
let non_empty = "foobar";
let empty2 = empty;
let non_empty2 = non_empty;
if empty2.is_empty() {
//~^ const_is_empty
}
if non_empty2.is_empty() {
//~^ const_is_empty
}
}
const EMPTY_STR: &str = "";
const NON_EMPTY_STR: &str = "foo";
const EMPTY_BSTR: &[u8] = b"";
const NON_EMPTY_BSTR: &[u8] = b"foo";
const EMPTY_U8_SLICE: &[u8] = &[];
const NON_EMPTY_U8_SLICE: &[u8] = &[1, 2];
const EMPTY_SLICE: &[u32] = &[];
const NON_EMPTY_SLICE: &[u32] = &[1, 2];
const NON_EMPTY_SLICE_REPEAT: &[u32] = &[1; 2];
const EMPTY_ARRAY: [u32; 0] = [];
const EMPTY_ARRAY_REPEAT: [u32; 0] = [1; 0];
const NON_EMPTY_ARRAY: [u32; 2] = [1, 2];
const NON_EMPTY_ARRAY_REPEAT: [u32; 2] = [1; 2];
const EMPTY_REF_ARRAY: &[u32; 0] = &[];
const NON_EMPTY_REF_ARRAY: &[u32; 3] = &[1, 2, 3];
fn test_from_const() {
let _ = EMPTY_STR.is_empty();
//~^ const_is_empty
let _ = NON_EMPTY_STR.is_empty();
//~^ const_is_empty
let _ = EMPTY_BSTR.is_empty();
//~^ const_is_empty
let _ = NON_EMPTY_BSTR.is_empty();
//~^ const_is_empty
let _ = EMPTY_ARRAY.is_empty();
//~^ const_is_empty
let _ = EMPTY_ARRAY_REPEAT.is_empty();
//~^ const_is_empty
let _ = EMPTY_U8_SLICE.is_empty();
//~^ const_is_empty
let _ = NON_EMPTY_U8_SLICE.is_empty();
//~^ const_is_empty
let _ = NON_EMPTY_ARRAY.is_empty();
//~^ const_is_empty
let _ = NON_EMPTY_ARRAY_REPEAT.is_empty();
//~^ const_is_empty
let _ = EMPTY_REF_ARRAY.is_empty();
//~^ const_is_empty
let _ = NON_EMPTY_REF_ARRAY.is_empty();
//~^ const_is_empty
let _ = EMPTY_SLICE.is_empty();
//~^ const_is_empty
let _ = NON_EMPTY_SLICE.is_empty();
//~^ const_is_empty
let _ = NON_EMPTY_SLICE_REPEAT.is_empty();
//~^ const_is_empty
}
fn main() {
let value = "foobar";
let _ = value.is_empty();
//~^ const_is_empty
let x = value;
let _ = x.is_empty();
//~^ const_is_empty
let _ = "".is_empty();
//~^ const_is_empty
let _ = b"".is_empty();
//~^ const_is_empty
}
fn str_from_arg(var: &str) {
var.is_empty();
// Do not lint, we know nothiny about var
}
fn update_str() {
let mut value = "duck";
value = "penguin";
let _ = value.is_empty();
// Do not lint since value is mutable
}
fn macros() {
// Content from Macro
let file = include_str!("const_is_empty.rs");
let _ = file.is_empty();
// No lint because initializer comes from a macro result
let var = env!("PATH");
let _ = var.is_empty();
// No lint because initializer comes from a macro result
}
fn conditional_value() {
let value;
if true {
value = "hey";
} else {
value = "hej";
}
let _ = value.is_empty();
// Do not lint, current constant folding is too simple to detect this
}
fn cfg_conditioned() {
#[cfg(test)]
let val = "";
#[cfg(not(test))]
let val = "foo";
let _ = val.is_empty();
// Do not lint, value depend on a #[cfg(…)] directive
}
fn not_cfg_conditioned() {
let val = "";
#[cfg(not(target_os = "inexistent"))]
let _ = val.is_empty();
//~^ const_is_empty
}
const fn const_rand() -> &'static str {
"17"
}
fn const_expressions() {
let _ = const { if true { "1" } else { "2" } }.is_empty();
// Do not lint, we do not recurse into boolean expressions
let _ = const_rand().is_empty();
// Do not lint, we do not recurse into functions
}
fn constant_from_external_crate() {
let _ = std::env::consts::EXE_EXTENSION.is_empty();
// Do not lint, `exe_ext` comes from the `std` crate
}
fn issue_13106() {
const {
assert!(!NON_EMPTY_STR.is_empty());
}
const {
assert!(EMPTY_STR.is_empty());
}
const {
EMPTY_STR.is_empty();
//~^ const_is_empty
}
}
|
