Struct wgpu_types::Features
source · [−]#[repr(transparent)]pub struct Features { /* private fields */ }
Expand description
Features that are not guaranteed to be supported.
These are either part of the webgpu standard, or are extension features supported by wgpu when targeting native.
If you want to use a feature, you need to first verify that the adapter supports the feature. If the adapter does not support the feature, requesting a device with it enabled will panic.
Corresponds to WebGPU GPUFeatureName
.
Implementations
sourceimpl Features
impl Features
sourcepub const DEPTH_CLIP_CONTROL: Self = _
pub const DEPTH_CLIP_CONTROL: Self = _
By default, polygon depth is clipped to 0-1 range before/during rasterization. Anything outside of that range is rejected, and respective fragments are not touched.
With this extension, we can disabling clipping. That allows shadow map occluders to be rendered into a tighter depth range.
Supported platforms:
- desktops
- some mobile chips
This is a web and native feature.
sourcepub const DEPTH24UNORM_STENCIL8: Self = _
pub const DEPTH24UNORM_STENCIL8: Self = _
Allows for explicit creation of textures of format TextureFormat::Depth24UnormStencil8
Supported platforms:
- Vulkan (some)
- DX12
- Metal (Macs with amd GPUs)
This is a web and native feature.
sourcepub const DEPTH32FLOAT_STENCIL8: Self = _
pub const DEPTH32FLOAT_STENCIL8: Self = _
Allows for explicit creation of textures of format TextureFormat::Depth32FloatStencil8
Supported platforms:
- Vulkan (mostly)
- DX12
- Metal
This is a web and native feature.
sourcepub const TEXTURE_COMPRESSION_BC: Self = _
pub const TEXTURE_COMPRESSION_BC: Self = _
Enables BCn family of compressed textures. All BCn textures use 4x4 pixel blocks with 8 or 16 bytes per block.
Compressed textures sacrifice some quality in exchange for significantly reduced bandwidth usage.
Support for this feature guarantees availability of [TextureUsages::COPY_SRC | TextureUsages::COPY_DST | TextureUsages::TEXTURE_BINDING
] for BCn formats.
Features::TEXTURE_ADAPTER_SPECIFIC_FORMAT_FEATURES
may enable additional usages.
Supported Platforms:
- desktops
This is a web and native feature.
sourcepub const TEXTURE_COMPRESSION_ETC2: Self = _
pub const TEXTURE_COMPRESSION_ETC2: Self = _
Enables ETC family of compressed textures. All ETC textures use 4x4 pixel blocks. ETC2 RGB and RGBA1 are 8 bytes per block. RTC2 RGBA8 and EAC are 16 bytes per block.
Compressed textures sacrifice some quality in exchange for significantly reduced bandwidth usage.
Support for this feature guarantees availability of [TextureUsages::COPY_SRC | TextureUsages::COPY_DST | TextureUsages::TEXTURE_BINDING
] for ETC2 formats.
Features::TEXTURE_ADAPTER_SPECIFIC_FORMAT_FEATURES
may enable additional usages.
Supported Platforms:
- Intel/Vulkan
- Mobile (some)
This is a web and native feature.
sourcepub const TEXTURE_COMPRESSION_ASTC_LDR: Self = _
pub const TEXTURE_COMPRESSION_ASTC_LDR: Self = _
Enables ASTC family of compressed textures. ASTC textures use pixel blocks varying from 4x4 to 12x12. Blocks are always 16 bytes.
Compressed textures sacrifice some quality in exchange for significantly reduced bandwidth usage.
Support for this feature guarantees availability of [TextureUsages::COPY_SRC | TextureUsages::COPY_DST | TextureUsages::TEXTURE_BINDING
] for ASTC formats.
Features::TEXTURE_ADAPTER_SPECIFIC_FORMAT_FEATURES
may enable additional usages.
Supported Platforms:
- Intel/Vulkan
- Mobile (some)
This is a web and native feature.
sourcepub const INDIRECT_FIRST_INSTANCE: Self = _
pub const INDIRECT_FIRST_INSTANCE: Self = _
Allows non-zero value for the “first instance” in indirect draw calls.
Supported Platforms:
- Vulkan (mostly)
- DX12
- Metal
This is a web and native feature.
sourcepub const TIMESTAMP_QUERY: Self = _
pub const TIMESTAMP_QUERY: Self = _
Enables use of Timestamp Queries. These queries tell the current gpu timestamp when
all work before the query is finished. Call [CommandEncoder::write_timestamp
],
[RenderPassEncoder::write_timestamp
], or [ComputePassEncoder::write_timestamp
] to
write out a timestamp.
They must be resolved using [CommandEncoder::resolve_query_sets
] into a buffer,
then the result must be multiplied by the timestamp period [Queue::get_timestamp_period
]
to get the timestamp in nanoseconds. Multiple timestamps can then be diffed to get the
time for operations between them to finish.
Due to wgpu-hal limitations, this is only supported on vulkan for now.
Supported Platforms:
- Vulkan (works)
- DX12 (works)
This is a web and native feature.
sourcepub const PIPELINE_STATISTICS_QUERY: Self = _
pub const PIPELINE_STATISTICS_QUERY: Self = _
Enables use of Pipeline Statistics Queries. These queries tell the count of various operations
performed between the start and stop call. Call [RenderPassEncoder::begin_pipeline_statistics_query
] to start
a query, then call [RenderPassEncoder::end_pipeline_statistics_query
] to stop one.
They must be resolved using [CommandEncoder::resolve_query_sets
] into a buffer.
The rules on how these resolve into buffers are detailed in the documentation for PipelineStatisticsTypes
.
Due to wgpu-hal limitations, this is only supported on vulkan for now.
Supported Platforms:
- Vulkan (works)
- DX12 (works)
This is a web and native feature.
sourcepub const SHADER_FLOAT16: Self = _
pub const SHADER_FLOAT16: Self = _
Allows shaders to acquire the FP16 ability
Note: this is not supported in naga yet,only through spir-v passthrough right now.
Supported Platforms:
- Vulkan
- Metal
This is a web and native feature.
sourcepub const MAPPABLE_PRIMARY_BUFFERS: Self = _
pub const MAPPABLE_PRIMARY_BUFFERS: Self = _
Webgpu only allows the MAP_READ and MAP_WRITE buffer usage to be matched with COPY_DST and COPY_SRC respectively. This removes this requirement.
This is only beneficial on systems that share memory between CPU and GPU. If enabled on a system that doesn’t, this can severely hinder performance. Only use if you understand the consequences.
Supported platforms:
- All
This is a native only feature.
sourcepub const TEXTURE_BINDING_ARRAY: Self = _
pub const TEXTURE_BINDING_ARRAY: Self = _
Allows the user to create uniform arrays of textures in shaders:
eg. uniform texture2D textures[10]
.
If Features::STORAGE_RESOURCE_BINDING_ARRAY
is supported as well as this, the user
may also create uniform arrays of storage textures.
eg. uniform image2D textures[10]
.
This capability allows them to exist and to be indexed by dynamically uniform values.
Supported platforms:
- DX12
- Metal (with MSL 2.0+ on macOS 10.13+)
- Vulkan
This is a native only feature.
sourcepub const BUFFER_BINDING_ARRAY: Self = _
pub const BUFFER_BINDING_ARRAY: Self = _
Allows the user to create arrays of buffers in shaders:
eg. uniform myBuffer { .... } buffer_array[10]
.
This capability allows them to exist and to be indexed by dynamically uniform values.
If Features::STORAGE_RESOURCE_BINDING_ARRAY
is supported as well as this, the user
may also create arrays of storage buffers.
eg. buffer myBuffer { ... } buffer_array[10]
Supported platforms:
- DX12
- Vulkan
This is a native only feature.
sourcepub const STORAGE_RESOURCE_BINDING_ARRAY: Self = _
pub const STORAGE_RESOURCE_BINDING_ARRAY: Self = _
Allows the user to create uniform arrays of storage buffers or textures in shaders,
if resp. Features::BUFFER_BINDING_ARRAY
or Features::TEXTURE_BINDING_ARRAY
is supported.
This capability allows them to exist and to be indexed by dynamically uniform values.
Supported platforms:
- Metal (with MSL 2.2+ on macOS 10.13+)
- Vulkan
This is a native only feature.
sourcepub const SAMPLED_TEXTURE_AND_STORAGE_BUFFER_ARRAY_NON_UNIFORM_INDEXING: Self = _
pub const SAMPLED_TEXTURE_AND_STORAGE_BUFFER_ARRAY_NON_UNIFORM_INDEXING: Self = _
Allows shaders to index sampled texture and storage buffer resource arrays with dynamically non-uniform values:
eg. texture_array[vertex_data]
In order to use this capability, the corresponding GLSL extension must be enabled like so:
#extension GL_EXT_nonuniform_qualifier : require
and then used either as nonuniformEXT
qualifier in variable declaration:
eg. layout(location = 0) nonuniformEXT flat in int vertex_data;
or as nonuniformEXT
constructor:
eg. texture_array[nonuniformEXT(vertex_data)]
HLSL does not need any extension.
Supported platforms:
- DX12
- Metal (with MSL 2.0+ on macOS 10.13+)
- Vulkan 1.2+ (or VK_EXT_descriptor_indexing)’s shaderSampledImageArrayNonUniformIndexing & shaderStorageBufferArrayNonUniformIndexing feature)
This is a native only feature.
sourcepub const UNIFORM_BUFFER_AND_STORAGE_TEXTURE_ARRAY_NON_UNIFORM_INDEXING: Self = _
pub const UNIFORM_BUFFER_AND_STORAGE_TEXTURE_ARRAY_NON_UNIFORM_INDEXING: Self = _
Allows shaders to index uniform buffer and storage texture resource arrays with dynamically non-uniform values:
eg. texture_array[vertex_data]
In order to use this capability, the corresponding GLSL extension must be enabled like so:
#extension GL_EXT_nonuniform_qualifier : require
and then used either as nonuniformEXT
qualifier in variable declaration:
eg. layout(location = 0) nonuniformEXT flat in int vertex_data;
or as nonuniformEXT
constructor:
eg. texture_array[nonuniformEXT(vertex_data)]
HLSL does not need any extension.
Supported platforms:
- DX12
- Metal (with MSL 2.0+ on macOS 10.13+)
- Vulkan 1.2+ (or VK_EXT_descriptor_indexing)’s shaderUniformBufferArrayNonUniformIndexing & shaderStorageTextureArrayNonUniformIndexing feature)
This is a native only feature.
sourcepub const PARTIALLY_BOUND_BINDING_ARRAY: Self = _
pub const PARTIALLY_BOUND_BINDING_ARRAY: Self = _
Allows the user to create bind groups continaing arrays with less bindings than the BindGroupLayout.
This is a native only feature.
sourcepub const MULTI_DRAW_INDIRECT: Self = _
pub const MULTI_DRAW_INDIRECT: Self = _
Allows the user to call [RenderPass::multi_draw_indirect
] and [RenderPass::multi_draw_indexed_indirect
].
Allows multiple indirect calls to be dispatched from a single buffer.
Supported platforms:
- DX12
- Vulkan
- Metal (Emulated on top of
draw_indirect
anddraw_indexed_indirect
)
This is a native only feature.
sourcepub const MULTI_DRAW_INDIRECT_COUNT: Self = _
pub const MULTI_DRAW_INDIRECT_COUNT: Self = _
Allows the user to call [RenderPass::multi_draw_indirect_count
] and [RenderPass::multi_draw_indexed_indirect_count
].
This allows the use of a buffer containing the actual number of draw calls.
Supported platforms:
- DX12
- Vulkan 1.2+ (or VK_KHR_draw_indirect_count)
This is a native only feature.
sourcepub const PUSH_CONSTANTS: Self = _
pub const PUSH_CONSTANTS: Self = _
Allows the use of push constants: small, fast bits of memory that can be updated
inside a [RenderPass
].
Allows the user to call [RenderPass::set_push_constants
], provide a non-empty array
to [PipelineLayoutDescriptor
], and provide a non-zero limit to Limits::max_push_constant_size
.
A block of push constants can be declared with layout(push_constant) uniform Name {..}
in shaders.
Supported platforms:
- DX12
- Vulkan
- Metal
- DX11 (emulated with uniforms)
- OpenGL (emulated with uniforms)
This is a native only feature.
sourcepub const ADDRESS_MODE_CLAMP_TO_BORDER: Self = _
pub const ADDRESS_MODE_CLAMP_TO_BORDER: Self = _
Allows the use of AddressMode::ClampToBorder
with a border color
other than SamplerBorderColor::Zero
.
Supported platforms:
- DX12
- Vulkan
- Metal (macOS 10.12+ only)
- DX11
- OpenGL
This is a web and native feature.
sourcepub const POLYGON_MODE_LINE: Self = _
pub const POLYGON_MODE_LINE: Self = _
Allows the user to set PolygonMode::Line
in PrimitiveState::polygon_mode
This allows drawing polygons/triangles as lines (wireframe) instead of filled
Supported platforms:
- DX12
- Vulkan
- Metal
This is a native only feature.
sourcepub const POLYGON_MODE_POINT: Self = _
pub const POLYGON_MODE_POINT: Self = _
Allows the user to set PolygonMode::Point
in PrimitiveState::polygon_mode
This allows only drawing the vertices of polygons/triangles instead of filled
Supported platforms:
- DX12
- Vulkan
This is a native only feature.
sourcepub const TEXTURE_ADAPTER_SPECIFIC_FORMAT_FEATURES: Self = _
pub const TEXTURE_ADAPTER_SPECIFIC_FORMAT_FEATURES: Self = _
Enables device specific texture format features.
See TextureFormatFeatures
for a listing of the features in question.
By default only texture format properties as defined by the WebGPU specification are allowed. Enabling this feature flag extends the features of each format to the ones supported by the current device. Note that without this flag, read/write storage access is not allowed at all.
This extension does not enable additional formats.
This is a native-only feature.
sourcepub const SHADER_FLOAT64: Self = _
pub const SHADER_FLOAT64: Self = _
Enables 64-bit floating point types in SPIR-V shaders.
Note: even when supported by GPU hardware, 64-bit floating point operations are frequently between 16 and 64 times slower than equivalent operations on 32-bit floats.
Supported Platforms:
- Vulkan
This is a native-only feature.
sourcepub const VERTEX_ATTRIBUTE_64BIT: Self = _
pub const VERTEX_ATTRIBUTE_64BIT: Self = _
Enables using 64-bit types for vertex attributes.
Requires SHADER_FLOAT64.
Supported Platforms: N/A
This is a native-only feature.
sourcepub const CONSERVATIVE_RASTERIZATION: Self = _
pub const CONSERVATIVE_RASTERIZATION: Self = _
Allows the user to set a overestimation-conservative-rasterization in PrimitiveState::conservative
Processing of degenerate triangles/lines is hardware specific. Only triangles are supported.
Supported platforms:
- Vulkan
This is a native only feature.
sourcepub const VERTEX_WRITABLE_STORAGE: Self = _
pub const VERTEX_WRITABLE_STORAGE: Self = _
Enables bindings of writable storage buffers and textures visible to vertex shaders.
Note: some (tiled-based) platforms do not support vertex shaders with any side-effects.
Supported Platforms:
- All
This is a native-only feature.
sourcepub const CLEAR_TEXTURE: Self = _
pub const CLEAR_TEXTURE: Self = _
Enables clear to zero for textures.
Supported platforms:
- All
This is a native only feature.
sourcepub const SPIRV_SHADER_PASSTHROUGH: Self = _
pub const SPIRV_SHADER_PASSTHROUGH: Self = _
Enables creating shader modules from SPIR-V binary data (unsafe).
SPIR-V data is not parsed or interpreted in any way; you can use
[wgpu::make_spirv_raw!
] to check for alignment and magic number when converting from
raw bytes.
Supported platforms:
- Vulkan, in case shader’s requested capabilities and extensions agree with Vulkan implementation.
This is a native only feature.
sourcepub const SHADER_PRIMITIVE_INDEX: Self = _
pub const SHADER_PRIMITIVE_INDEX: Self = _
Enables builtin(primitive_index)
in fragment shaders.
Note: enables geometry processing for pipelines using the builtin. This may come with a significant performance impact on some hardware. Other pipelines are not affected.
Supported platforms:
- Vulkan
This is a native only feature.
sourcepub const MULTIVIEW: Self = _
pub const MULTIVIEW: Self = _
Enables multiview render passes and builtin(view_index)
in vertex shaders.
Supported platforms:
- Vulkan
This is a native only feature.
sourcepub const TEXTURE_FORMAT_16BIT_NORM: Self = _
pub const TEXTURE_FORMAT_16BIT_NORM: Self = _
Enables normalized 16-bit
texture formats.
Supported platforms:
- Vulkan
- DX12
- Metal
This is a native only feature.
sourcepub const ADDRESS_MODE_CLAMP_TO_ZERO: Self = _
pub const ADDRESS_MODE_CLAMP_TO_ZERO: Self = _
Allows the use of AddressMode::ClampToBorder
with a border color
of SamplerBorderColor::Zero
.
Supported platforms:
- DX12
- Vulkan
- Metal
- DX11
- OpenGL
This is a native only feature.
sourcepub const TEXTURE_COMPRESSION_ASTC_HDR: Self = _
pub const TEXTURE_COMPRESSION_ASTC_HDR: Self = _
Enables ASTC HDR family of compressed textures.
Compressed textures sacrifice some quality in exchange for significantly reduced bandwidth usage.
Support for this feature guarantees availability of [TextureUsages::COPY_SRC | TextureUsages::COPY_DST | TextureUsages::TEXTURE_BINDING
] for BCn formats.
Features::TEXTURE_ADAPTER_SPECIFIC_FORMAT_FEATURES
may enable additional usages.
Supported Platforms:
- Metal
This is a native-only feature.
sourcepub const WRITE_TIMESTAMP_INSIDE_PASSES: Self = _
pub const WRITE_TIMESTAMP_INSIDE_PASSES: Self = _
Allows for timestamp queries inside renderpasses. Metal does not allow this on Apple GPUs.
Implies [Features::TIMESTAMP_QUERIES
] is supported.
Supported platforms:
- Vulkan
- DX12
- Metal (Intel and AMD GPUs)
sourcepub const fn from_bits(bits: u64) -> Option<Self>
pub const fn from_bits(bits: u64) -> Option<Self>
Convert from underlying bit representation, unless that representation contains bits that do not correspond to a flag.
sourcepub const fn from_bits_truncate(bits: u64) -> Self
pub const fn from_bits_truncate(bits: u64) -> Self
Convert from underlying bit representation, dropping any bits that do not correspond to flags.
sourcepub const unsafe fn from_bits_unchecked(bits: u64) -> Self
pub const unsafe fn from_bits_unchecked(bits: u64) -> Self
Convert from underlying bit representation, preserving all bits (even those not corresponding to a defined flag).
Safety
The caller of the bitflags!
macro can chose to allow or
disallow extra bits for their bitflags type.
The caller of from_bits_unchecked()
has to ensure that
all bits correspond to a defined flag or that extra bits
are valid for this bitflags type.
sourcepub const fn intersects(&self, other: Self) -> bool
pub const fn intersects(&self, other: Self) -> bool
Returns true
if there are flags common to both self
and other
.
sourcepub const fn contains(&self, other: Self) -> bool
pub const fn contains(&self, other: Self) -> bool
Returns true
if all of the flags in other
are contained within self
.
sourcepub fn set(&mut self, other: Self, value: bool)
pub fn set(&mut self, other: Self, value: bool)
Inserts or removes the specified flags depending on the passed value.
sourcepub const fn intersection(self, other: Self) -> Self
pub const fn intersection(self, other: Self) -> Self
Returns the intersection between the flags in self
and
other
.
Specifically, the returned set contains only the flags which are
present in both self
and other
.
This is equivalent to using the &
operator (e.g.
ops::BitAnd
), as in flags & other
.
sourcepub const fn union(self, other: Self) -> Self
pub const fn union(self, other: Self) -> Self
Returns the union of between the flags in self
and other
.
Specifically, the returned set contains all flags which are
present in either self
or other
, including any which are
present in both (see Self::symmetric_difference
if that
is undesirable).
This is equivalent to using the |
operator (e.g.
ops::BitOr
), as in flags | other
.
sourcepub const fn difference(self, other: Self) -> Self
pub const fn difference(self, other: Self) -> Self
Returns the difference between the flags in self
and other
.
Specifically, the returned set contains all flags present in
self
, except for the ones present in other
.
It is also conceptually equivalent to the “bit-clear” operation:
flags & !other
(and this syntax is also supported).
This is equivalent to using the -
operator (e.g.
ops::Sub
), as in flags - other
.
sourcepub const fn symmetric_difference(self, other: Self) -> Self
pub const fn symmetric_difference(self, other: Self) -> Self
Returns the symmetric difference between the flags
in self
and other
.
Specifically, the returned set contains the flags present which
are present in self
or other
, but that are not present in
both. Equivalently, it contains the flags present in exactly
one of the sets self
and other
.
This is equivalent to using the ^
operator (e.g.
ops::BitXor
), as in flags ^ other
.
sourcepub const fn complement(self) -> Self
pub const fn complement(self) -> Self
Returns the complement of this set of flags.
Specifically, the returned set contains all the flags which are
not set in self
, but which are allowed for this type.
Alternatively, it can be thought of as the set difference
between Self::all()
and self
(e.g. Self::all() - self
)
This is equivalent to using the !
operator (e.g.
ops::Not
), as in !flags
.
sourceimpl Features
impl Features
sourcepub const fn all_webgpu_mask() -> Self
pub const fn all_webgpu_mask() -> Self
Mask of all features which are part of the upstream WebGPU standard.
sourcepub const fn all_native_mask() -> Self
pub const fn all_native_mask() -> Self
Mask of all features that are only available when targeting native (not web).
Trait Implementations
sourceimpl BitAndAssign<Features> for Features
impl BitAndAssign<Features> for Features
sourcefn bitand_assign(&mut self, other: Self)
fn bitand_assign(&mut self, other: Self)
Disables all flags disabled in the set.
sourceimpl BitOrAssign<Features> for Features
impl BitOrAssign<Features> for Features
sourcefn bitor_assign(&mut self, other: Self)
fn bitor_assign(&mut self, other: Self)
Adds the set of flags.
sourceimpl BitXorAssign<Features> for Features
impl BitXorAssign<Features> for Features
sourcefn bitxor_assign(&mut self, other: Self)
fn bitxor_assign(&mut self, other: Self)
Toggles the set of flags.
sourceimpl Extend<Features> for Features
impl Extend<Features> for Features
sourcefn extend<T: IntoIterator<Item = Self>>(&mut self, iterator: T)
fn extend<T: IntoIterator<Item = Self>>(&mut self, iterator: T)
Extends a collection with the contents of an iterator. Read more
sourcefn extend_one(&mut self, item: A)
fn extend_one(&mut self, item: A)
extend_one
)Extends a collection with exactly one element.
sourcefn extend_reserve(&mut self, additional: usize)
fn extend_reserve(&mut self, additional: usize)
extend_one
)Reserves capacity in a collection for the given number of additional elements. Read more
sourceimpl FromIterator<Features> for Features
impl FromIterator<Features> for Features
sourcefn from_iter<T: IntoIterator<Item = Self>>(iterator: T) -> Self
fn from_iter<T: IntoIterator<Item = Self>>(iterator: T) -> Self
Creates a value from an iterator. Read more
sourceimpl Ord for Features
impl Ord for Features
sourceimpl PartialOrd<Features> for Features
impl PartialOrd<Features> for Features
sourcefn partial_cmp(&self, other: &Features) -> Option<Ordering>
fn partial_cmp(&self, other: &Features) -> Option<Ordering>
This method returns an ordering between self
and other
values if one exists. Read more
1.0.0 · sourcefn lt(&self, other: &Rhs) -> bool
fn lt(&self, other: &Rhs) -> bool
This method tests less than (for self
and other
) and is used by the <
operator. Read more
1.0.0 · sourcefn le(&self, other: &Rhs) -> bool
fn le(&self, other: &Rhs) -> bool
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
sourceimpl SubAssign<Features> for Features
impl SubAssign<Features> for Features
sourcefn sub_assign(&mut self, other: Self)
fn sub_assign(&mut self, other: Self)
Disables all flags enabled in the set.
impl Copy for Features
impl Eq for Features
impl StructuralEq for Features
impl StructuralPartialEq for Features
Auto Trait Implementations
impl RefUnwindSafe for Features
impl Send for Features
impl Sync for Features
impl Unpin for Features
impl UnwindSafe for Features
Blanket Implementations
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more