Struct show_notes::e029::Point

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#[repr(C)]
pub struct Point { pub x: c_float, pub y: c_float, }
Expand description

An example of a slightly more complex data structure we can use with FFI.

Note the #[repr(C)], which tells Rust to make sure this struct is laid out the way that the C ABI expects. That’s not the way that Rust’s own ABI (which is unstable and can change at any time) might lay it out.

Note also that x and y are c_float, which is a type alias for f32. We use it here to make explicit the interop, and also because it is possible that it might change on some specific operating system. If we went to compile for an operating system where C’s float type were not a 32-point floating bit number (and the C standard does not require it to be anything but “a floating point number”), the compiler would let us know.

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§x: c_float§y: c_float

Trait Implementations§

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impl Debug for Point

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

Formats the value using the given formatter. Read more
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impl PartialEq for Point

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

This method tests for self and other values to be equal, and is used by ==.
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fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.
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impl StructuralPartialEq for Point

Auto Trait Implementations§

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impl Freeze for Point

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impl RefUnwindSafe for Point

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impl Send for Point

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impl Sync for Point

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impl Unpin for Point

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impl UnwindSafe for Point

Blanket Implementations§

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T, U> TryFrom<U> for T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.