Enum Predicate

pub enum Predicate<'a> {
    Target(TargetPredicate),
    Test,
    DebugAssertions,
    ProcMacro,
    Feature(&'a str),
    TargetFeature(&'a str),
    Flag(&'a str),
    KeyValue {
        key: &'a str,
        val: &'a str,
    },
}

A single predicate in a cfg() expression

Variants

Target(TargetPredicate)

A target predicate, with the target_ prefix

Test

Whether rustc’s test harness is enabled

DebugAssertions

Enabled when compiling without optimizations.

ProcMacro

Enabled for crates of the proc_macro type.

Feature(&'a str)

A feature = "<name>"

TargetFeature(&'a str)

target_feature

Flag(&'a str)

A generic bare predicate key that doesn’t match one of the known options, eg cfg(bare)

KeyValue

A generic key = “value” predicate that doesn’t match one of the known options, eg cfg(foo = "bar")

Fields

key: &'a str

val: &'a str

Trait Implementations

impl<'a> Debug for Predicate<'a>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'a> PartialEq for Predicate<'a>

fn eq(&self, other: &Predicate<'a>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<'a> Eq for Predicate<'a>

impl<'a> StructuralPartialEq for Predicate<'a>