# Introspection > USearch for Swift ```swift let description = try index.describe() print(description.metadata.dimensions, description.metadata.connectivity) print(description.size, description.capacity, description.memoryUsage, description.cpuClass, description.shardsCount) print(try index.count(key: 42), try index.contains(key: 42)) let reachability = try index.on(executor).health() print(reachability.reachable, "of", reachability.audited, "entries reachable after", reachability.sweeps, "sweeps") print(version(), capabilitiesCompiled(), capabilitiesAvailable()) ``` `health` audits how much of the graph a search reaches from its landmarks; entries it misses stay unfound until a `refine` re-links them. `import USearch` ## CPUClass A CPU family USearch ships tuned variants for; dispatch reports its pick in this vocabulary, and a RAM or NVMe placement or executor may pin one. ```swift struct CPUClass ``` Conforms to: `Hashable`, `Sendable`, `CustomStringConvertible`, `Equatable` ## serial The portable floor, with no SIMD assumptions. ```swift static let serial: CPUClass ``` ## intelHaswell Haswell-class x86: AVX2 and FMA. ```swift static let intelHaswell: CPUClass ``` ## intelSierra Sierra Forest-class x86: AVX-VNNI without AVX-512. ```swift static let intelSierra: CPUClass ``` ## intelSkylake Skylake-class x86: the AVX-512 foundation. ```swift static let intelSkylake: CPUClass ``` ## intelIcelake Icelake-class x86: AVX-512 VNNI and VPOPCNT. ```swift static let intelIcelake: CPUClass ``` ## amdGenoa Genoa-class x86: native bf16 dot products over AVX-512. ```swift static let amdGenoa: CPUClass ``` ## intelSapphire Sapphire Rapids-class x86: AVX-512 FP16 and the AMX tiles. ```swift static let intelSapphire: CPUClass ``` ## intelGranite Granite Rapids-class x86: the AMX-FP16 tiles. ```swift static let intelGranite: CPUClass ``` ## intelDiamond Diamond Rapids-class x86: AVX10.2's FP8 conversions. ```swift static let intelDiamond: CPUClass ``` ## awsG2 Graviton2-class Arm: the bare NEON floor. ```swift static let awsG2: CPUClass ``` ## appleM2 Armv8.6 NEON with dot products and bf16. ```swift static let appleM2: CPUClass ``` ## appleM4 Apple M4-class Arm: the SME outer-product tiles. ```swift static let appleM4: CPUClass ``` ## awsG5 Graviton5-class Arm: Armv9.2. ```swift static let awsG5: CPUClass ``` ## nvidiaVera Vera-class Arm: FP8 dot products. ```swift static let nvidiaVera: CPUClass ``` ## alibabaC930 Alibaba C930-class RISC-V: RVA23 vectors. ```swift static let alibabaC930: CPUClass ``` ## wasm32V128 WebAssembly with fixed-width simd128. ```swift static let wasm32V128: CPUClass ``` ## wasm64Extended WebAssembly with relaxed SIMD, threads and 64-bit addressing. ```swift static let wasm64Extended: CPUClass ``` ## monoversioned The one class of a monoversioned build. ```swift static let monoversioned: CPUClass ``` ## description The class as the library spells it. ```swift var description: String { get } ``` ## init Reads a spelling back, and nil for one no class carries. ```swift init?(name: String) ``` ## GPUClass A GPU family USearch ships tuned variants for; a VRAM placement or executor may pin one. ```swift struct GPUClass ``` Conforms to: `Hashable`, `Sendable`, `CustomStringConvertible`, `Equatable` ## nvidiaAmpere Ampere-class NVIDIA, and every NVIDIA GPU without a class of its own. ```swift static let nvidiaAmpere: GPUClass ``` ## nvidiaAda Ada-class NVIDIA: the fp8 conversions. ```swift static let nvidiaAda: GPUClass ``` ## nvidiaHopper Hopper-class NVIDIA. ```swift static let nvidiaHopper: GPUClass ``` ## nvidiaBlackwell Blackwell-class NVIDIA. ```swift static let nvidiaBlackwell: GPUClass ``` ## nvidiaBlackwellRTX Consumer Blackwell NVIDIA. ```swift static let nvidiaBlackwellRTX: GPUClass ``` ## nvidiaRubin Rubin-class NVIDIA. ```swift static let nvidiaRubin: GPUClass ``` ## amdCDNA3 CDNA3 AMD: gfx942. ```swift static let amdCDNA3: GPUClass ``` ## amdCDNA4 CDNA4 AMD: gfx950. ```swift static let amdCDNA4: GPUClass ``` ## amdCDNA5 CDNA5 AMD: gfx1250. ```swift static let amdCDNA5: GPUClass ``` ## appleMetal7 Apple7-family GPUs, and every Apple GPU without a class of its own. ```swift static let appleMetal7: GPUClass ``` ## appleMetal9 Apple9-family GPUs. ```swift static let appleMetal9: GPUClass ``` ## appleMetal10 Apple10-family GPUs. ```swift static let appleMetal10: GPUClass ``` ## description The class as the library spells it. ```swift var description: String { get } ``` ## init Reads a spelling back, and nil for one no class carries. ```swift init?(name: String) ``` ## DenseIndexDescription A live index's frozen metadata and current counters, each read once, so under concurrent insertions they may come from slightly different moments. ```swift struct DenseIndexDescription ``` Conforms to: `Sendable` ## metadata The frozen metric, quantization, dimensions and connectivity, as a checkpoint reports them. ```swift var metadata: DenseMetadata ``` ## size The stored entries. ```swift var size: Int ``` ## capacity The entries hosted without growing again. ```swift var capacity: Int ``` ## memoryUsage The bytes the handle holds; traversal scratch is the executor's. ```swift var memoryUsage: Int ``` ## cpuClass The CPU class whose kits the index dispatched to on RAM and NVMe; nil on VRAM. ```swift var cpuClass: CPUClass? ``` ## gpuClass The GPU class whose kernels the index dispatched to on VRAM; nil on RAM and NVMe. ```swift var gpuClass: GPUClass? ``` ## shardsCount The live shards, each a graph of its own. ```swift var shardsCount: Int ``` ## DenseReachability One reachability audit: the population it judged, and how much of it a search reaches. ```swift struct DenseReachability ``` Conforms to: `Equatable`, `Sendable` ## audited The entries published when the audit started; compare [`reachable`](#reachable) against this, never a later size. ```swift var audited: Int ``` ## reachable Of those, the entries a search reaches from the landmarks; the rest no search finds until a refinement re-links them. ```swift var reachable: Int ``` ## sweeps The levels the sweep took to converge. ```swift var sweeps: Int ``` ## backSweeps The levels the sweep back toward the entry point took, where an audit sweeps both ways. ```swift var backSweeps: Int ``` ## version The version of the linked library, like `3.0.0`. ```swift func version() -> String ``` ## capabilitiesCompiled The hardware capabilities the linked binary was compiled with, comma separated. ```swift func capabilitiesCompiled() -> String ``` ## capabilitiesAvailable The hardware capabilities the current machine offers at runtime, comma separated. ```swift func capabilitiesAvailable() -> String ```