Module rust_2021

The 2021 version of the core prelude.

See the module-level documentation for more.

Macros

• assert
  Asserts that a boolean expression is true at runtime.
• cfg
  Evaluates boolean combinations of configuration flags at compile-time.
• column
  Expands to the column number at which it was invoked.
• compile_error
  Causes compilation to fail with the given error message when encountered.
• concat
  Concatenates literals into a static string slice.
• env
  Inspects an environment variable at compile time.
• file
  Expands to the file name in which it was invoked.
• format_args
  Constructs parameters for the other string-formatting macros.
• include
  Parses a file as an expression or an item according to the context.
• include_bytes
  Includes a file as a reference to a byte array.
• include_str
  Includes a UTF-8 encoded file as a string.
• line
  Expands to the line number on which it was invoked.
• module_path
  Expands to a string that represents the current module path.
• option_env
  Optionally inspects an environment variable at compile time.
• stringify
  Stringifies its arguments.
• concat_bytesExperimental
  Concatenates literals into a byte slice.
• concat_identsExperimental
  Concatenates identifiers into one identifier.
• derefExperimental
  Unstable placeholder for deref patterns.
• format_args_nlExperimental
  Same as format_args, but adds a newline in the end.
• log_syntaxExperimental
  Prints passed tokens into the standard output.
• trace_macrosExperimental
  Enables or disables tracing functionality used for debugging other macros.
• type_ascribeExperimental
  Unstable placeholder for type ascription.

Enums

• Option
  The Option type. See the module level documentation for more.
• Result
  Result is a type that represents either success (Ok) or failure (Err).

Traits

• AsMut
  Used to do a cheap mutable-to-mutable reference conversion.
• AsRef
  Used to do a cheap reference-to-reference conversion.
• Clone
  A common trait for the ability to explicitly duplicate an object.
• Copy
  Types whose values can be duplicated simply by copying bits.
• Default
  A trait for giving a type a useful default value.
• DoubleEndedIterator
  An iterator able to yield elements from both ends.
• Drop
  Custom code within the destructor.
• Eq
  Trait for comparisons corresponding to equivalence relations.
• ExactSizeIterator
  An iterator that knows its exact length.
• Extend
  Extend a collection with the contents of an iterator.
• Fn
  The version of the call operator that takes an immutable receiver.
• FnMut
  The version of the call operator that takes a mutable receiver.
• FnOnce
  The version of the call operator that takes a by-value receiver.
• From
  Used to do value-to-value conversions while consuming the input value. It is the reciprocal of Into.
• FromIterator
  Conversion from an Iterator.
• Into
  A value-to-value conversion that consumes the input value. The opposite of From.
• IntoIterator
  Conversion into an Iterator.
• Iterator
  A trait for dealing with iterators.
• Ord
  Trait for types that form a total order.
• PartialEq
  Trait for comparisons using the equality operator.
• PartialOrd
  Trait for types that form a partial order.
• Send
  Types that can be transferred across thread boundaries.
• Sized
  Types with a constant size known at compile time.
• Sync
  Types for which it is safe to share references between threads.
• TryFrom
  Simple and safe type conversions that may fail in a controlled way under some circumstances. It is the reciprocal of TryInto.
• TryInto
  An attempted conversion that consumes self, which may or may not be expensive.
• Unpin
  Types that do not require any pinning guarantees.

Functions

• align_of
  Returns the ABI-required minimum alignment of a type in bytes.
• align_of_val
  Returns the ABI-required minimum alignment of the type of the value that val points to in bytes.
• drop
  Disposes of a value.
• size_of
  Returns the size of a type in bytes.
• size_of_val
  Returns the size of the pointed-to value in bytes.

Attribute Macros

• derive
  Attribute macro used to apply derive macros.
• global_allocator
  Attribute macro applied to a static to register it as a global allocator.
• test
  Attribute macro applied to a function to turn it into a unit test.
• alloc_error_handlerExperimental
  Attribute macro applied to a function to register it as a handler for allocation failure.
• benchExperimental
  Attribute macro applied to a function to turn it into a benchmark test.
• cfg_accessibleExperimental
  Keeps the item it’s applied to if the passed path is accessible, and removes it otherwise.
• cfg_evalExperimental
  Expands all #[cfg] and #[cfg_attr] attributes in the code fragment it’s applied to.
• derive_constExperimental
  Attribute macro used to apply derive macros for implementing traits in a const context.
• test_caseExperimental
  An implementation detail of the #[test] and #[bench] macros.

Derive Macros

• Clone
  Derive macro generating an impl of the trait Clone.
• Copy
  Derive macro generating an impl of the trait Copy.
• Debug
  Derive macro generating an impl of the trait Debug.
• Default
  Derive macro generating an impl of the trait Default.
• Eq
  Derive macro generating an impl of the trait Eq.
• Hash
  Derive macro generating an impl of the trait Hash.
• Ord
  Derive macro generating an impl of the trait Ord. The behavior of this macro is described in detail here.
• PartialEq
  Derive macro generating an impl of the trait PartialEq. The behavior of this macro is described in detail here.
• PartialOrd
  Derive macro generating an impl of the trait PartialOrd. The behavior of this macro is described in detail here.