Cargo Features

[dependencies]
zng-var = { version = "0.4.4", default-features = false, features = ["debug_default", "dyn_closure"] }
default = debug_default

The debug_default feature is set by default whenever zng-var is added without default-features = false somewhere in the dependency tree.

debug_default default

Signal the build script to enable the "dyn_*" features in debug builds.

dyn_closure

Box closures at opportune places, such as Var::map, reducing the number of monomorphised types.

This speeds-up compilation time at the cost of runtime.