Struct abi_stable::sabi_types::Constructor

#[repr(transparent)]
pub struct Constructor<T>(pub extern "C" fn() -> T);

Newtype wrapper to pass function pointers to const fn.

Every impl of this type delegates the impl to the return value of the wrapped function (which it calls every time),don't use those impls if the function is likely expensive.

Example

use abi_stable::{
    sabi_types::Constructor,
    std_types::{ROption,RNone,RSome},
};


extern "C" fn returns_100()->ROption<u32>{
    RSome(100)
}

extern "C" fn returns_100b()->ROption<u32>{
    RSome(100)
}

extern "C" fn returns_200()->ROption<u32>{
    RSome(200)
}

extern "C" fn returns_none()->ROption<u32>{
    RNone
}


const A: Constructor<ROption<u32>>= Constructor(returns_100);
const B: Constructor<ROption<u32>>= Constructor(returns_100b);
const C: Constructor<ROption<u32>>= Constructor(returns_200);
const D: Constructor<ROption<u32>>= Constructor(returns_none);

assert_eq!(A,A);
assert_eq!(B,B);
assert_eq!(C,C);
assert_eq!(D,D);

assert_eq!(A,B);

assert_ne!(A,C);
assert_ne!(A,D);
assert_ne!(B,C);
assert_ne!(C,D);

Methods

impl<T> Constructor<T>

pub fn get(self) -> T

Constructs a T by calling the wrapped function.

Trait Implementations

impl<T> Clone for Constructor<T>

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T> Copy for Constructor<T>

impl<T> Debug for Constructor<T> where
    T: Debug, 

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

Formats the value using the given formatter.

impl<T> Display for Constructor<T> where
    T: Display, 

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

Formats the value using the given formatter.

impl<T> Eq for Constructor<T> where
    T: Eq, 

impl<T> GetStaticEquivalent_ for Constructor<T> where
    T: __StableAbi, 

type StaticEquivalent = _static_Constructor<__GetStaticEquivalent<T>>

impl<T> Ord for Constructor<T> where
    T: Ord, 

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

🔬 This is a nightly-only experimental API. (clamp)

Restrict a value to a certain interval.

impl<T> PartialEq<Constructor<T>> for Constructor<T> where
    T: PartialEq, 

fn eq(&self, other: &Self) -> bool

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl<T> PartialOrd<Constructor<T>> for Constructor<T> where
    T: PartialOrd, 

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

#[must_use] fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

#[must_use] fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

#[must_use] fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

#[must_use] fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<T> SharedStableAbi for Constructor<T> where
    T: __StableAbi, 

type IsNonZeroType = True

Whether this type has a single invalid bit-pattern.

type Kind = __ValueKind

The kind of abi stability of this type,there are 2:

const S_LAYOUT: &'static TypeLayout

The layout of the type provided by implementors.

const S_ABI_CONSTS: AbiConsts