Crate prelude

Expand description

import prelude::* so you can be ready to code!

§Traits

Not having common traits imported is one of the most annoying gotchas in rust when coming from other languages. When you are used to the language, you expect the methods you are used to to always work… not so. Using Vec::from_iter is extremely common, but you must first import the FromIterator trait.

The following are the traits that are implemented and why:

std::ascii::AsciiExt: adds the to_ascii_uppercase onto &str types.
std::fmt::Debug: allows you to define Debug manually.
std::fmt::Write as FmtWrite: adds write_str onto byte buffers (such as String). Renamed FmtWrite to avoid conflict with std::io::Write
std::io::Read: allows you to use file.read()
std::io::Seek: allows you to use file.seek()
std::io::Write as IoWrite: allows you to use file.write() and file.write_all(). Renamed IoWrite to avoid conflict with std::fmt::Write
std::ops::{Deref, DerefMut}: allows deref through *v and also enables Deref coercions
std::str::FromStr: allows you to use type::from_str constructor for several types. This is what is implicitly called with str::parse<_>()

§structs

These are extremely commonly used types and it is annoying to have to reimport them all the time.

std::collections::{BTreeMap, HashMap, HashSet}: ordered-dict, dict and set
std::ffi::OsString: os agnostic (non unicode) string type std::path::PathBuf uses this.
std::fs::File: for opening files.
- File::open to open a file for reading
- File::write to open a file for writing
std::fs::OpenOptions for more file opening options
std::fs::ReadDir: to iterate over the entries in a directory.
std::path::{Path, PathBuf}: specifies an os path.
std::rc::Rc: reference counted pointer
std::sync::Arc: atomically reference counted pointer
std::sync::Mutex: mutual exclusion primitive for threading.
std::sync::atomic::{AtomicBool, AtomicIsize, AtomicUsize}: basic atomic types. Good for unique ids and lots of other use cases.
std::sync::atomic::Ordering: necessary for performing operations on atomic types. For incrementing a counter use val.fetch_add(1, Ordering::SeqCst).
std::sync::atomic::ATOMIC_USIZE_INIT: initialized AtomicUsize of 0. Use with static COUNTER: AtomicUsize = ATOMIC_USIZE_INIT;
std::time::Duration: an amount of time, used for std::thread::sleep.

§functions

std::mem::{size_of, size_of_val}: get the size of a type. This is safe and common enough that it should be always available.
std::thread::sleep: put the thread to sleep for a Duration.
std::thread::spawn: spawn a function in a new thread. In rust this is memory safe, so it is nice to have it always available.

Structs§

Arc: A thread-safe reference-counting pointer. ‘Arc’ stands for ‘Atomically Reference Counted’.
AtomicBool: A boolean type which can be safely shared between threads.
AtomicIsize: An integer type which can be safely shared between threads.
AtomicUsize: An integer type which can be safely shared between threads.
BTreeMap: An ordered map based on a B-Tree.
Duration: A Duration type to represent a span of time, typically used for system timeouts.
File: An object providing access to an open file on the filesystem.
HashMap: A hash map implemented with quadratic probing and SIMD lookup.
HashSet: A hash set implemented as a HashMap where the value is ().
Mutex: A mutual exclusion primitive useful for protecting shared data
OpenOptions: Options and flags which can be used to configure how a file is opened.
OsString: A type that can represent owned, mutable platform-native strings, but is cheaply inter-convertible with Rust strings.
Path: A slice of a path (akin to str).
PathBuf: An owned, mutable path (akin to String).
Rc: A single-threaded reference-counting pointer. ‘Rc’ stands for ‘Reference Counted’.
ReadDir: Iterator over the entries in a directory.

Enums§

Ordering: Atomic memory orderings
SeekFrom: Enumeration of possible methods to seek within an I/O object.

Constants§

ATOMIC_USIZE_INITDeprecated: An AtomicUsize initialized to 0.

Traits§

AsciiExtDeprecated: Extension methods for ASCII-subset only operations.
Debug: ? formatting.
Deref: Used for immutable dereferencing operations, like *v.
DerefMut: Used for mutable dereferencing operations, like in *v = 1;.
FmtWrite: A trait for writing or formatting into Unicode-accepting buffers or streams.
FromIterator: Conversion from an Iterator.
FromStr: Parse a value from a string
IoWrite: A trait for objects which are byte-oriented sinks.
Read: The Read trait allows for reading bytes from a source.
Seek: The Seek trait provides a cursor which can be moved within a stream of bytes.

Functions§

size_of: Returns the size of a type in bytes.
size_of_val: Returns the size of the pointed-to value in bytes.
sleep: Puts the current thread to sleep for at least the specified amount of time.
spawn: Spawns a new thread, returning a JoinHandle for it.

Derive Macros§

Debug: Derive macro generating an impl of the trait Debug.

Crate preludeCopy item path