For now, this reference is a best-effort document. We strive for validity and completeness, but are not yet there. In the future, the docs and lang teams will work together to figure out how best to do this. Until then, this is a best-effort attempt. If you find something wrong or missing, file an issue or send in a pull request.


Rust divides keywords into three categories:

Strict keywords

These keywords can only be used in their correct contexts. For example, it is not allowed to declare a variable with name struct.

KW_AS : as
KW_BOX : box
KW_BREAK : break
KW_CONST : const
KW_CONTINUE : continue
KW_CRATE : crate
KW_ELSE : else
KW_ENUM : enum
KW_EXTERN : extern
KW_FALSE : false
KW_FN : fn
KW_FOR : for
KW_IF : if
KW_IMPL : impl
KW_IN : in
KW_LET : let
KW_LOOP : loop
KW_MATCH : match
KW_MOD : mod
KW_MOVE : move
KW_MUT : mut
KW_PUB : pub
KW_REF : ref
KW_RETURN : return
KW_STATIC : static
KW_STRUCT : struct
KW_SUPER : super
KW_TRAIT : trait
KW_TRUE : true
KW_TYPE : type
KW_UNSAFE : unsafe
KW_USE : use
KW_WHERE : where
KW_WHILE : while

Weak keywords

These keywords have special meaning only in certain contexts. For example, it is possible to declare a variable or method with the name union.

KW_CATCH : catch
KW_DEFAULT : default
KW_UNION : union

Reserved keywords

These keywords aren't used yet, but they are reserved for future use. The reasoning behind this is to make current programs forward compatible with future versions of Rust by forbidding them to use these keywords.

KW_ABSTRACT : abstract
KW_ALIGNOF : alignof
KW_BECOME : become
KW_DO : do
KW_FINAL : final
KW_MACRO : macro
KW_OFFSETOF : offsetof
KW_OVERRIDE : override
KW_PRIV : priv
KW_PROC : proc
KW_PURE : pure
KW_SIZEOF : sizeof
KW_TYPEOF : typeof
KW_UNSIZED : unsized
KW_VIRTUAL : virtual
KW_YIELD : yield