Feature flags

This crate exposes a number of features. These can be enabled or disabled as shown in Cargo's documentation. Features are disabled by default unless otherwise noted.

Reliance on a given feature is always indicated alongside the item definition.

• std (enabled by default, implicitly enables alloc)

  This enables a number of features that depend on the standard library.

• alloc (enabled by default via std)

  Enables a number of features that require the ability to dynamically allocate memory.

• macros

  Enables macros that provide compile-time verification of values and intuitive syntax.

• formatting (implicitly enables std)

  Enables formatting of most structs.

• parsing

  Enables parsing of most structs.

• local-offset (implicitly enables std)

  This feature enables a number of methods that allow obtaining the system's UTC offset.

• large-dates

  By default, only years within the ±9999 range (inclusive) are supported. If you need support for years outside this range, consider enabling this feature; the supported range will be increased to ±999,999.

  Note that enabling this feature has some costs, as it means forgoing some optimizations. Ambiguities may be introduced when parsing that would not otherwise exist.

• serde

  Enables serde support for all types.

• serde-human-readable (implicitly enables serde, formatting, and parsing)

  Allows serde representations to use a human-readable format. This is determined by the serializer, not the user. If this feature is not enabled or if the serializer requests a non-human-readable format, a format optimized for binary representation will be used.

  Libraries should never enable this feature, as the decision of what format to use should be up to the user.

• rand (implicitly enables rand08 and rand09)

  Previously, this would enable support for rand 0.8. Since the release of rand 0.9, the feature has been split into rand08 and rand09 to allow support for both versions. For backwards compatibility and simplicity, this feature enables support for both series.

  It is strongly recommended to enable rand08 or rand09 directly, as enabling rand will needlessly pull in both versions.

• rand08

  Enables rand 0.8 support for all types.

• rand09

  Enables rand 0.9 support for all types.

• quickcheck (implicitly enables alloc)

  Enables quickcheck support for all types.

• wasm-bindgen

  Enables wasm-bindgen support for converting JavaScript dates, as well as obtaining the UTC offset from JavaScript.