Overview

Raw byte buffers with numeric lanes in either byte order.

ByteBuffer is a fixed-size block of bytes with an address, a length, and endian-aware accessors for the usual integer and float widths. Use it for file contents, network frames, C ABI calls, and hand-written wire formats, where the byte order and the lane width both matter.

The size is picked once by allocate and never changes: there is no resize, so length() and capacity() always report the same number. Out-of-range access is neither clamped nor reported as an error value. A read or write that reaches past the end, or starts at a negative offset, stops the program with byte buffer out of bounds. A negative capacity stops it with negative byte buffer capacity.

Offsets and sizes are plain Int. Narrow integer lanes widen into a 64-bit Int on the way out: signed lanes sign-extend, unsigned lanes zero-extend. Float lanes widen the same way, and the 32-bit float accessors narrow a Float to 32 bits on the way in, which leaves about 7 decimal digits.

The LE and BE suffixes pick the byte order. Little-endian puts the least significant byte at the lowest offset, which is what x86, ARM, and most desktop formats use. Big-endian puts the most significant byte at the lowest offset, which is network byte order and what most file formats use. Write a lane with the same order you read it with; mixing the two on one field is a common source of silent corruption.

Build a buffer with fromString or fromArray for text and byte lists, or with allocate plus the write* methods for anything else. slice copies a range out into a new buffer, and copyWithin shifts a range inside the buffer that already exists. address hands the raw pointer to Pointer.fromAddress for unsafe work and C calls.

When to use it

Reach for @std/bytes when a program talks to the outside world in binary: wire protocols, file headers, or any format where byte order matters. Text stays in String; everything else goes through a ByteBuffer.

Capabilities

• Fixed-size raw buffers
• Explicit-endian int/float lanes
• Zero-copy slicing

Symbols

• class ByteBuffer — Fixed-size raw byte buffer. All offsets and sizes are plain Int;
• fn utf8Len()