std - Standard Library

The std namespace is the root of Zig’s standard library and provides access to all standard library functionality.

Overview

The Zig standard library is imported with:

const std = @import("std");

This gives you access to all the standard library’s data structures, algorithms, and system interfaces.

Data Structures

ArrayList

fn(comptime T: type) type

A contiguous, growable list of items in memory. This is a wrapper around a slice of T values.The same allocator must be used throughout its entire lifetime. Initialize directly with empty or initCapacity, and deinitialize with deinit or toOwnedSlice.Example:

const std = @import("std");
const ArrayList = std.ArrayList;

var list = ArrayList(u8).init(allocator);
defer list.deinit();

try list.append(1);
try list.append(2);

Hash Maps

ArrayHashMap

type

Hash map with array-based storage for cache-friendly iteration. Maintains insertion order.

ArrayHashMapUnmanaged

type

Unmanaged variant of ArrayHashMap that does not store an allocator internally.

AutoArrayHashMap

type

ArrayHashMap that automatically selects hash and equality functions based on key type.

AutoHashMap

type

HashMap that automatically selects hash and equality functions based on key type.

HashMap

type

General-purpose hash map implementation.

HashMapUnmanaged

type

Unmanaged variant of HashMap that does not store an allocator internally.

StringHashMap

type

HashMap specialized for string keys.

StringArrayHashMap

type

ArrayHashMap specialized for string keys.

Bit Sets

DynamicBitSet

type

Dynamically-sized bit set with allocator management.

StaticBitSet

type

Fixed-size bit set with compile-time known size.

Lists and Queues

DoublyLinkedList

type

A doubly-linked list implementation.

SinglyLinkedList

type

A singly-linked list implementation.

Deque

type

Double-ended queue allowing efficient insertion and removal at both ends.

PriorityQueue

type

Min-heap or max-heap based priority queue.

PriorityDequeue

type

Priority queue that supports removal from both ends.

Other Data Structures

MultiArrayList

type

Structure-of-arrays list for improved cache locality.

EnumArray

type

Array indexed by enum values.

EnumMap

type

Map using enum values as keys.

EnumSet

type

Set of enum values.

Treap

type

Randomized binary search tree.

Core Modules

Memory Management

mem

module

Memory utilities including comparison, copying, and manipulation functions.Location: lib/std/mem.zig

heap

module

Memory allocators including GeneralPurposeAllocator, ArenaAllocator, and page_allocator.Location: lib/std/heap.zig

Debugging and Testing

debug

module

Debugging utilities including assertions, stack traces, and panic handlers.Location: lib/std/debug.zig

testing

module

Testing utilities for unit tests.Location: lib/std/testing.zig

log

module

Logging functionality with configurable levels and scopes.Location: lib/std/log.zig

Formatting and I/O

fmt

module

String formatting and parsing utilities.Location: lib/std/fmt.zig

module

Filesystem operations and directory handling.Location: lib/std/fs.zig

type

I/O operations and abstractions.Location: lib/std/Io.zig

System Interfaces

module

Operating system specific functionality (being phased out in favor of posix).Location: lib/std/os.zig

posix

module

POSIX system calls and interfaces.Location: lib/std/posix.zig

process

module

Process-related functionality including argument parsing and environment variables.Location: lib/std/process.zig

Thread

type

Threading primitives and utilities.Location: lib/std/Thread.zig

Text Processing

ascii

module

ASCII character classification and manipulation.Location: lib/std/ascii.zig

unicode

module

Unicode utilities and UTF encoding/decoding.Location: lib/std/unicode.zig

Data Formats

json

module

JSON parsing and stringification.Location: lib/std/json.zig

zon

module

ZON (Zig Object Notation) parser.Location: lib/std/zon.zig

base64

module

Base64 encoding and decoding.Location: lib/std/base64.zig

Compression and Archives

compress

module

Compression algorithms (gzip, deflate, etc.).Location: lib/std/compress.zig

tar

module

TAR archive format handling.Location: lib/std/tar.zig

zip

module

ZIP archive format handling.Location: lib/std/zip.zig

Cryptography

crypto

module

Cryptographic primitives including hashing, encryption, and signatures.Location: lib/std/crypto.zig

Mathematics

math

module

Mathematical functions and constants.Location: lib/std/math.zig

simd

module

SIMD (Single Instruction Multiple Data) utilities.Location: lib/std/simd.zig

Networking

http

module

HTTP client and server utilities.Location: lib/std/http.zig

Binary Formats

elf

module

ELF (Executable and Linkable Format) parser.Location: lib/std/elf.zig

macho

module

Mach-O executable format parser.Location: lib/std/macho.zig

coff

module

COFF (Common Object File Format) parser.Location: lib/std/coff.zig

dwarf

module

DWARF debug information format.Location: lib/std/dwarf.zig

pdb

module

PDB (Program Database) debug format.Location: lib/std/pdb.zig

wasm

module

WebAssembly format utilities.Location: lib/std/wasm.zig

Utilities

hash

module

Hash functions (not cryptographic).Location: lib/std/hash.zig

sort

module

Sorting algorithms.Location: lib/std/sort.zig

Build System

Build

type

The build system API for build.zig files.See std.Build API Reference for complete documentation.Location: lib/std/Build.zig

Other Types

Target

type

Target architecture, OS, and ABI information.Location: lib/std/Target.zig

SemanticVersion

type

Semantic versioning parser and utilities.Location: lib/std/SemanticVersion.zig

Uri

type

URI parsing and manipulation.Location: lib/std/Uri.zig

Random

type

Random number generation.Location: lib/std/Random.zig

Progress

type

Progress reporting for long-running operations.Location: lib/std/Progress.zig

DynLib

type

Dynamic library loading.Location: lib/std/dynamic_library.zig

BufMap

type

String-to-string hash map.Location: lib/std/buf_map.zig

BufSet

type

Set of strings.Location: lib/std/buf_set.zig

StaticStringMap

type

Compile-time string map.Location: lib/std/static_string_map.zig

Configuration

options

Options

Stdlib-wide options that can be overridden by the root file.Set by defining std_options in your root source file:

pub const std_options = .{
    .log_level = .debug,
    .enable_segfault_handler = true,
};

Show Options Fields

enable_segfault_handler

bool

default:"depends on mode"

Enable the segfault handler.

log_level

log.Level

default:".info"

The current log level.

log_scope_levels

[]const log.ScopeLevel

default:"&.{}"

Per-scope log level configuration.

logFn

function

Custom logging function.

page_size_min

?usize

default:"null"

Overrides std.heap.page_size_min.

page_size_max

?usize

default:"null"

Overrides std.heap.page_size_max.

http_disable_tls

bool

default:"false"

Disable TLS support in std.http.Client to reduce binary size.

allow_stack_tracing

bool

default:"!builtin.strip_debug_info"

Whether to allow capturing and writing stack traces.

Core

Data Structures

Memory

System

Utilities

std - Standard Library

Overview

Data Structures

ArrayList

Hash Maps

Bit Sets

Lists and Queues

Other Data Structures

Core Modules

Memory Management

Debugging and Testing

Formatting and I/O

System Interfaces

Text Processing

Data Formats

Compression and Archives

Cryptography

Mathematics

Networking

Binary Formats

Utilities

Build System

Other Types

Configuration

See Also

Build docs developers (and LLMs) love

Core

Data Structures

Memory

System

Utilities

​Overview

​Data Structures

​ArrayList

​Hash Maps

​Bit Sets

​Lists and Queues

​Other Data Structures

​Core Modules

​Memory Management

​Debugging and Testing

​Formatting and I/O

​System Interfaces

​Text Processing

​Data Formats

​Compression and Archives

​Cryptography

​Mathematics

​Networking

​Binary Formats

​Utilities

​Build System

​Other Types

​Configuration

​See Also

Build docs developers (and LLMs) love

Overview

Data Structures

ArrayList

Hash Maps

Bit Sets

Lists and Queues

Other Data Structures

Core Modules

Memory Management

Debugging and Testing

Formatting and I/O

System Interfaces

Text Processing

Data Formats

Compression and Archives

Cryptography

Mathematics

Networking

Binary Formats

Utilities

Build System

Other Types

Configuration

See Also