Trait SimdAlphabet 

trait SimdAlphabet {
    const ENCODE_LUT: [i8; 16];
    const DECODE_SHIFT_LUT: [i8; 16];
    const DECODE_MASK_LUT: [u8; 16];
    const DECODE_FIXUP_CHAR: i8;
    const DECODE_FIXUP_SHIFT: i8;
}

A base64 alphabet family the SIMD kernels can accelerate.

Carries the per-alphabet lookup tables as associated constants. Private (hence sealed); implemented only by Standard and UrlSafe, selected at runtime by SimdKind.

Required Associated Constants

const ENCODE_LUT: [i8; 16]

pshufb encode table: maps a reduced 6-bit index to ascii - index.

const DECODE_SHIFT_LUT: [i8; 16]

pshufb decode table indexed by the high nibble; added to the byte to produce its 6-bit value.

const DECODE_MASK_LUT: [u8; 16]

pshufb decode table indexed by the low nibble; bit hi marks (hi, lo) as a valid symbol.

const DECODE_FIXUP_CHAR: i8

The high-62/63 symbol whose shift needs the fixup below (+/-).

const DECODE_FIXUP_SHIFT: i8

The shift applied to DECODE_FIXUP_CHAR.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl SimdAlphabet for Standard

Available on AArch64 or x86-64 only.

const ENCODE_LUT: [i8; 16]

const DECODE_SHIFT_LUT: [i8; 16]

const DECODE_MASK_LUT: [u8; 16]

const DECODE_FIXUP_CHAR: i8 = 0x2F

const DECODE_FIXUP_SHIFT: i8 = 16

impl SimdAlphabet for UrlSafe

Available on AArch64 or x86-64 only.

const ENCODE_LUT: [i8; 16]

const DECODE_SHIFT_LUT: [i8; 16]

const DECODE_MASK_LUT: [u8; 16]

const DECODE_FIXUP_CHAR: i8 = 0x5F

const DECODE_FIXUP_SHIFT: i8 = -32