Rust Learn

Start

Install

# installing `rustup` on Linux or macOS
curl https://sh.rustup.rs -sSf | sh

export PATH="$HOME/.cargo/bin:$PATH"

Updating & Uninstalling

rustup update

rustup self uninstall

Troubleshooting

rustc

rustup

cargo
cargo new
cargo check
cargo run
cargo build [--release]
cargo doc [--open]
cargo test

# If you don’t want to run the tests in parallel
# or if you want more fine-grained control over the number of threads used
# We set the number of test threads to 1, telling the program not to use any parallelism.
cargo test -- --test-threads=1

# disable the output capture behavior
cargo test -- --nocapture

# Filtering to Run Multiple Tests
# note that the module in which a test appears becomes part of the test’s name,
# so we can run all the tests in a module by filtering on the module’s name.
cargo test <fn_part_name>

# run only the ignored tests
cargo test -- --ignored

# to run all the tests in a particular integration test file
cargo test --test <filename>

# run tests for one particular crate in a workspace from the top-level directory
cargo test -p <crate_name>

cargo login <API_TOKEN>
cargo publish
# `--undo`: By adding `--undo` to the command, you can also undo a yank and allow projects to start depending on a version again
cargo yank --vers <version> [--undo]

cargo install <binary_crate>

Cargo.toml

[package]
name = "pack_name" # the name of the package
version = "pack_version" # the current version, obeying semver
authors = ["name <[email protected]>"]
edition = "2018"

[profile.dev]
opt-level = 0

[profile.release]
opt-level = 3

[dependencies]

[workspace]
members = ["..."]

Local Documentation

rustup doc

Data Types

• Integer Types

  Length	Signed	Unsigned
  8-bit	i8	u8
  16-bit	i16	u16
  32-bit	i32	u32
  64-bit	i64	u64
  128-bit	i128	u128
  arch	isize	usize

  • signed: -2^n-1 ～ 2^n-1-1
  • unsigned: 0 ～ 2ⁿ-1
  • isize & usize: 64 bits (64-bit architecture), 32 bits (32-bit architecture)

• Floating-Point Types

f32, f64(default): The f32 type is a single-precision float, and f64 has double precision.

• The Boolean Type: bool

• The Character Type: char

• Compound Types:

  • The Tuple Type: tuple

  tuple: A finite heterogeneous sequence, (T, U, ..).

  • The Array Type: array slice

  array: A fixed-size array, denoted [T; N], for the element type, T, and the non-negative compile-time constant size, N.

  slice: A dynamically-sized view into a contiguous sequence, [T].

Documentation

Documentation comments within items are useful for describing crates and modules especially. Use them to explain the overall purpose of the container to help your users understand the crate’s organization.

• ///: documentation comments, support Markdown notation for formatting the text.
• //!: adds documentation to the item that contains the comments rather than adding documentation to the items following the comments.

Commonly Used Sections

• Panics: The scenarios in which the function being documented could panic. Callers of the function who don’t want their programs to panic should make sure they don’t call the function in these situations.
• Errors: If the function returns a Result, describing the kinds of errors that might occur and what conditions might cause those errors to be returned can be helpful to callers so they can write code to handle the different kinds of errors in different ways.
• Safety: If the function is unsafe to call, there should be a section explaining why the function is unsafe and covering the invariants that the function expects callers to uphold.

Attributes

/** syntax */
// InnerAttribute:
#![Attr]

// OuterAttribute:
#[Attr]

Built-in attributes	attribute	description
Conditional compilation	cfg	controls conditional compilation
	cfg_attr	conditionally includes attributes
Testing	test	marks a function as a test
	ignore	disables a test function
	should_panic	indicates a test should generate a panic.
Derive	derive	automatic trait implementations
Macros	macro_export	exports a macro_rules macro for cross-crate usage
	macro_use	expands macro visibility, or imports macros from other crates
	proc_macro	defines a function-like macro
	proc_macro_derive	defines a derive macro
	proc_macro_attribute	defines an attribute macro
Diagnostics	allow, warn, deny, forbid	alters the default lint level
	deprecated	generates deprecation notices
	must_use	generates a lint for unused values
ABI, linking, symbols, and FFI	link	specifies a native library to link with an extern block
	link_name	specifies the name of the symbol for functions or statics in an extern block
	no_link	prevents linking an extern crate
	repr	controls type layout
	crate_type	specifies the type of crate (library, executable, etc.)
	no_main	disables emitting the main symbol
	export_name	specifies the exported symbol name for a function or static
	link_section	specifies the section of an object file to use for a function or static
	no_mangle	disables symbol name encoding
	used	forces the compiler to keep a static item in the output object file
	crate_name	specifies the crate name
Code generation	inline	hint to inline code
	cold	hint that a function is unlikely to be called
	no_builtins	disables use of certain built-in functions
	target_feature	configure platform-specific code generation
Documentation	doc	specifies documentation. See The Rustdoc Book for more information. Doc comments are transformed into doc attributes
Preludes	no_std	removes std from the prelude
	no_implicit_prelude	disables prelude lookups within a module
Modules	path	specifies the filename for a module
Limits	recursion_limit	sets the maximum recursion limit for certain compile-time operations
	type_length_limit	sets the maximum size of a polymorphic type
Runtime	panic_handler	sets the function to handle panics
	global_allocator	sets the global memory allocator
	windows_subsystem	specifies the windows subsystem to link with
Features	feature	used to enable unstable or experimental compiler features. See The Unstable Book for features implemented in rustc

/** Diagnostics */
// overrides the check for C so that violations will go unreported
#[allow(C)]
// warns about violations of C but continues compilation
#[warn(C)]
// signals an error after encountering a violation of C
#[deny(C)]
// is the same as deny(C), but also forbids changing the lint level afterwards
#[forbid(C)]
// since: specifies a version number when the item was deprecated
// note: specifies a string that should be included in the deprecation message
#[deprecated(since = "", note="")]
// is used to issue a diagnostic warning when a value is not "used"
#[must_use]


/** Code generation */
// suggests performing an inline expansion.
#[inline]
// suggests that an inline expansion should always be performed.
#[inline(always)]
// suggests that an inline expansion should never be performed.
#[inline(never)]

/** Testing */
#[test]
#[ignore]
#[should_panic]

Concept

• Object-Oriented: Object-oriented programs are made up of objects. An object packages both data and the procedures that operate on that data. The procedures are typically called methods or operations.
• Polymorphism: To many people, polymorphism is synonymous with inheritance. But it’s actually a more general concept that refers to code that can work with data of multiple types. For inheritance, those types are generally subclasses.
  Rust instead uses generics to abstract over different possible types and trait bounds to impose constraints on what those types must provide. This is sometimes called bounded parametric polymorphism.

Related Links

• A closer look at Ownership in Rusts