[−][src]Struct lv2_sys::LV2_URI_Map_Feature
URI Map Feature.
To support this feature the host must pass an LV2_Feature struct to the plugin's instantiate method with URI "http://lv2plug.in/ns/ext/uri-map" and data pointed to an instance of this struct.
Fields
callback_data: LV2_URI_Map_Callback_Data
Opaque pointer to host data.
The plugin MUST pass this to any call to functions in this struct. Otherwise, it must not be interpreted in any way.
uri_to_id: Option<unsafe extern "C" fn(callback_data: LV2_URI_Map_Callback_Data, map: *const c_char, uri: *const c_char) -> u32>
Get the numeric ID of a URI from the host.
@param callback_data Must be the callback_data member of this struct. @param map The 'context' of this URI. Certain extensions may define a URI that must be passed here with certain restrictions on the return value (e.g. limited range). This value may be NULL if the plugin needs an ID for a URI in general. Extensions SHOULD NOT define a context unless there is a specific need to do so, e.g. to restrict the range of the returned value. @param uri The URI to be mapped to an integer ID.
This function is referentially transparent; any number of calls with the same arguments is guaranteed to return the same value over the life of a plugin instance (though the same URI may return different values with a different map parameter). However, this function is not necessarily very fast: plugins SHOULD cache any IDs they might need in performance critical situations.
The return value 0 is reserved and indicates that an ID for that URI could not be created for whatever reason. Extensions MAY define more precisely what this means in a certain context, but in general plugins SHOULD handle this situation as gracefully as possible. However, hosts SHOULD NOT return 0 from this function in non-exceptional circumstances (e.g. the URI map SHOULD be dynamic). Hosts that statically support only a fixed set of URIs should not expect plugins to function correctly.
Trait Implementations
impl Clone for LV2_URI_Map_Feature
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fn clone(&self) -> LV2_URI_Map_Feature
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fn clone_from(&mut self, source: &Self)
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impl Copy for LV2_URI_Map_Feature
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impl Debug for LV2_URI_Map_Feature
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Auto Trait Implementations
impl RefUnwindSafe for LV2_URI_Map_Feature
impl !Send for LV2_URI_Map_Feature
impl !Sync for LV2_URI_Map_Feature
impl Unpin for LV2_URI_Map_Feature
impl UnwindSafe for LV2_URI_Map_Feature
Blanket Implementations
impl<T> Any for T where
T: 'static + ?Sized,
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T: 'static + ?Sized,
impl<T> Borrow<T> for T where
T: ?Sized,
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T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
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T: ?Sized,
pub fn borrow_mut(&mut self) -> &mut T
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impl<T> From<T> for T
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impl<T, U> Into<U> for T where
U: From<T>,
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U: From<T>,
impl<T> ToOwned for T where
T: Clone,
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T: Clone,
type Owned = T
The resulting type after obtaining ownership.
pub fn to_owned(&self) -> T
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pub fn clone_into(&self, target: &mut T)
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impl<T, U> TryFrom<U> for T where
U: Into<T>,
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U: Into<T>,
type Error = Infallible
The type returned in the event of a conversion error.
pub fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>
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impl<T, U> TryInto<U> for T where
U: TryFrom<T>,
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U: TryFrom<T>,