Module snafu::guide::feature_flags
source · [−]Expand description
Optional extensions to the crate
In addition to the feature flags controlling compatibility, there are Cargo feature flags that extend SNAFU for various use cases:
stdunstable-core-errorguidebacktracesbacktraces-impl-backtrace-cratebacktraces-impl-stdunstable-backtraces-impl-stdunstable-provider-apifuturesunstable-try-trait
std
When enabled, SNAFU will implement the std::error::Error trait. When
disabled, SNAFU will instead implement a custom Error trait that is
similar, but does not need any features from the standard library.
See also unstable-core-error.
Most usages of SNAFU will want this feature enabled.
unstable-core-error
When enabled, SNAFU will implement the core::error::Error trait,
even when the std feature flag is also enabled.
guide
When enabled, the guide module containing the user’s guide will be
built.
Most usages of SNAFU will want this feature disabled.
backtraces
When enabled, the Backtrace type in your enum variant will capture
a backtrace when the error is generated. If you never use backtraces,
you can omit this feature to speed up compilation a small amount.
It is recommended that only applications make use of this feature.
backtraces-impl-backtrace-crate
When enabled, the SNAFU Backtrace type becomes an alias to the
backtrace::Backtrace type. This allows interoperability with other
crates that require this type.
It is recommended that only applications make use of this feature. When the standard library stabilizes its own backtrace type, this feature will no longer be supported and will be removed.
backtraces-impl-std
When enabled, the SNAFU Backtrace type becomes an alias to the
std::backtrace::Backtrace type.
It is recommended that only applications make use of this feature.
unstable-backtraces-impl-std
When enabled, the std::error::Error::backtrace method is implemented.
It is recommended that only applications make use of this feature.
unstable-provider-api
When enabled, SNAFU-generated errors will implement the
std::error::Error::provide method, allowing data to be retrieved
using request_ref and request_value on a std::error::Error
trait object reference. Provided data can be controlled using
#[snafu(provide)].
It is recommended that only applications make use of this feature.
futures
When enabled, you can use the futures::TryFutureExt and
futures::TryStreamExt traits to add context methods to futures
and streams returning Results.
unstable-try-trait
default: disabled
When enabled, the ? operator can be used on Result values in
functions where a Report type is returned.
It is recommended that only applications make use of this feature.