Method from_descriptor

crates/cust/src/memory/array.rs:317–481

Constructs a generic ArrayObject from an `ArrayDescriptor`.

(descriptor: &ArrayDescriptor)

    /// Constructs a generic ArrayObject from an `ArrayDescriptor`.
    pub fn from_descriptor(descriptor: &ArrayDescriptor) -> CudaResult<Self> {
        // We validate the descriptor up front in debug mode. This provides a good error message to
        // the user when they get something wrong, but doesn't re-validate in release mode.
        if cfg!(debug_assertions) {
            assert_ne!(
                0,
                descriptor.width(),
                "Cannot allocate an array with 0 Width"
            );

            if !descriptor.flags().contains(ArrayObjectFlags::LAYERED) && descriptor.depth() > 0 {
                assert_ne!(
                    0,
                    descriptor.height(),
                    "If Depth is non-zero and the descriptor is not LAYERED, then Height must also \
                    be non-zero."
                );
            }

            if descriptor.flags().contains(ArrayObjectFlags::CUBEMAP) {
                assert_eq!(
                    descriptor.height(),
                    descriptor.width(),
                    "Height and Width must be equal for CUBEMAP arrays."
                );

                if descriptor.flags().contains(ArrayObjectFlags::LAYERED) {
                    assert_eq!(
                        0,
                        descriptor.depth() % 6,
                        "Depth must be a multiple of 6 when the array descriptor is for a LAYERED \
                         CUBEMAP."
                    );
                } else {
                    assert_eq!(
                        6,
                        descriptor.depth(),
                        "Depth must be equal to 6 when the array descriptor is for a CUBEMAP."
                    );
                }
            }

            assert!(
                descriptor.num_channels() == 1
                    || descriptor.num_channels() == 2
                    || descriptor.num_channels() == 4,
                "NumChannels was set to {}. It must be 1, 2, or 4.",
                descriptor.num_channels()
            );

            // Exhaustively check bounds of arrays
            let device = CurrentContext::get_device()?;

            let attr = |attr| Ok(1..=(device.get_attribute(attr)? as usize));

            let (description, bounds) = if descriptor.flags().contains(ArrayObjectFlags::CUBEMAP) {
                if descriptor.flags().contains(ArrayObjectFlags::LAYERED) {
                    (