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// Copyright 2022 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
use crate::{
description::Description,
matcher::{Matcher, MatcherBase, MatcherResult},
};
use num_traits::float::Float;
use std::fmt::Debug;
/// Matches a floating point value which is NaN.
pub fn is_nan() -> IsNanMatcher {
IsNanMatcher
}
#[derive(MatcherBase)]
pub struct IsNanMatcher;
impl<T: Float + Debug + Copy> Matcher<T> for IsNanMatcher {
fn matches(&self, actual: T) -> MatcherResult {
actual.is_nan().into()
}
fn describe(&self, matcher_result: MatcherResult) -> Description {
if matcher_result.into() { "is NaN" } else { "isn't NaN" }.into()
}
}
#[cfg(test)]
mod tests {
use crate::prelude::*;
use crate::Result;
#[test]
fn matches_f32_nan() -> Result<()> {
verify_that!(f32::NAN, is_nan())
}
#[test]
fn does_not_match_f32_number() -> Result<()> {
verify_that!(0.0f32, not(is_nan()))
}
#[test]
fn matches_f64_nan() -> Result<()> {
verify_that!(f64::NAN, is_nan())
}
#[test]
fn does_not_match_f64_number() -> Result<()> {
verify_that!(0.0f64, not(is_nan()))
}
}