Struct PredicateMatcher 

pub struct PredicateMatcher<P, D1, D2> { /* private fields */ }

A matcher which applies predicate on the value.

See predicate.

Implementations

impl<P> PredicateMatcher<P, NoDescription, NoDescription>

pub fn with_description<D1: PredicateDescription, D2: PredicateDescription>( self, positive_description: D1, negative_description: D2, ) -> PredicateMatcher<P, D1, D2>

Configures this instance to provide a more meaningful description.

For example, to make sure the error message is more useful

predicate(|x: i32| x % 2 == 1)
    .with_description("is odd", "is even")

This is optional as it only provides value when the test fails.

Description can be passed by &str, String or Fn() -> Into<String>.

Trait Implementations

impl<T: Debug + Copy, P, D1: PredicateDescription, D2: PredicateDescription> Matcher<T> for PredicateMatcher<P, D1, D2>

where P: Fn(T) -> bool,

fn matches(&self, actual: T) -> MatcherResult

Returns whether the condition matches the datum actual.

fn describe(&self, result: MatcherResult) -> Description

Returns a description of self or a negative description if matcher_result is DoesNotMatch.

fn explain_match(&self, actual: ActualT) -> Description

Prepares a String describing how the expected value encoded in this instance matches or does not match the given value actual.

impl<P, D1, D2> MatcherBase for PredicateMatcher<P, D1, D2>

fn and<Right>(self, right: Right) -> ConjunctionMatcher<Self, Right>

where Self: Sized,

Constructs a matcher that matches both self and right.

fn or<Right>(self, right: Right) -> DisjunctionMatcher<Self, Right>

where Self: Sized,

Constructs a matcher that matches when at least one of self or right matches the input.