num_enum
Procedural macros to make inter-operation between primitives and enums easier. This crate is no_std compatible.
Turning an enum into a primitive
use IntoPrimitive;
num_enum
's IntoPrimitive
is more type-safe than using as
, because as
will silently truncate - num_enum
only derives From
for exactly the discriminant type of the enum.
Attempting to turn a primitive into an enum with try_from
use TryFromPrimitive;
use TryFrom;
Unsafely turning a primitive into an enum with from_unchecked
If you're really certain a conversion will succeed, and want to avoid a small amount of overhead, you can use unsafe
code to do this conversion. Unless you have data showing that the match statement generated in the try_from
above is a
bottleneck for you, you should avoid doing this, as the unsafe code has potential to cause serious memory issues in
your program.
use UnsafeFromPrimitive;
unsafe
Optional features
Some enum values may be composed of complex expressions, for example:
To cut down on compile time, these are not supported by default, but if you enable the complex-expressions
feature of your dependency on num_enum
, these should start working.