Auto merge of #4214 - d-dorazio:4204-fix-float-cmp-neq, r=flip1995

fix suggestion for floating point inequality

It should be of the form `(a - b).abs() > error` whereas it was `(a - b).abs() < error` that is instead what should be used for equality.

fixes #4204.

changelog: fix suggestion for floating point inequality
This commit is contained in:
bors 2019-06-17 15:18:31 +00:00
commit ab085d9aea
3 changed files with 9 additions and 5 deletions

View File

@ -387,7 +387,11 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MiscLints {
db.span_suggestion(
expr.span,
"consider comparing them within some error",
format!("({}).abs() < error", lhs - rhs),
format!(
"({}).abs() {} error",
lhs - rhs,
if op == BinOpKind::Eq { '<' } else { '>' }
),
Applicability::MachineApplicable, // snippet
);
db.span_note(expr.span, "std::f32::EPSILON and std::f64::EPSILON are available.");

View File

@ -2,7 +2,7 @@ error: strict comparison of f32 or f64
--> $DIR/float_cmp.rs:60:5
|
LL | ONE as f64 != 2.0;
| ^^^^^^^^^^^^^^^^^ help: consider comparing them within some error: `(ONE as f64 - 2.0).abs() < error`
| ^^^^^^^^^^^^^^^^^ help: consider comparing them within some error: `(ONE as f64 - 2.0).abs() > error`
|
= note: `-D clippy::float-cmp` implied by `-D warnings`
note: std::f32::EPSILON and std::f64::EPSILON are available.
@ -27,7 +27,7 @@ error: strict comparison of f32 or f64
--> $DIR/float_cmp.rs:68:5
|
LL | twice(x) != twice(ONE as f64);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider comparing them within some error: `(twice(x) - twice(ONE as f64)).abs() < error`
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider comparing them within some error: `(twice(x) - twice(ONE as f64)).abs() > error`
|
note: std::f32::EPSILON and std::f64::EPSILON are available.
--> $DIR/float_cmp.rs:68:5

View File

@ -27,7 +27,7 @@ error: strict comparison of f32 or f64 constant
--> $DIR/float_cmp_const.rs:20:5
|
LL | TWO != ONE;
| ^^^^^^^^^^ help: consider comparing them within some error: `(TWO - ONE).abs() < error`
| ^^^^^^^^^^ help: consider comparing them within some error: `(TWO - ONE).abs() > error`
|
note: std::f32::EPSILON and std::f64::EPSILON are available.
--> $DIR/float_cmp_const.rs:20:5
@ -75,7 +75,7 @@ error: strict comparison of f32 or f64 constant
--> $DIR/float_cmp_const.rs:27:5
|
LL | v != ONE;
| ^^^^^^^^ help: consider comparing them within some error: `(v - ONE).abs() < error`
| ^^^^^^^^ help: consider comparing them within some error: `(v - ONE).abs() > error`
|
note: std::f32::EPSILON and std::f64::EPSILON are available.
--> $DIR/float_cmp_const.rs:27:5