std.derives.* (reference)

This page documents the derive-related trait families available under std.derives.*. Import these traits when you want to adopt them explicitly or refer to them in annotations and bounds.

Related pages

• If you want the language-facing explanation of derives, trait authoring, and conflict rules, see: Language → Reference → Derives & traits.
• If you want the per-family reference pages, see: Comparison, Copying and Default, and String representation.

Importing derive traits

Import from the specific derive submodule:

from std.derives.comparison import Eq, Ord, Hash
from std.derives.copying import Clone, Copy, Default
from std.derives.string import Debug, Display
from std.derives.collection import Contains, Bool, Len, Iterable, Iterator

Surface model

Traits under std.derives.* describe capabilities such as equality, ordering, copying, and display formatting.

• Many of these traits are also the ones used by @derive(...).
• You can import the trait names directly when you want to refer to them in type-level positions.
• The collection traits in std.derives.collection are ordinary trait families for collection-like behavior, not derive markers.

Submodules

std.derives.comparison

Provides:

• Eq
• Ord
• Hash

See Comparison.

std.derives.copying

Provides:

• Clone
• Copy
• Default

See Copying and Default.

std.derives.string

Provides:

• Debug
• Display

See String representation.

std.derives.collection

Provides collection-protocol traits for custom types, including:

• Contains[T]
• Bool
• Len
• Iterable[T]
• Iterator[T]

Use these when you want a custom type to participate in collection-style APIs through explicit trait adoption. Bool is available, but prefer explicit checks for Option, Result, emptiness, and named boolean state when that is the behavior you mean.