Cargo Features

[dependencies]
actix-flash = { version = "0.2.0", default-features = false, features = ["v2", "v3"] }
default = v3

The v3 feature is set by default whenever actix-flash is added without default-features = false somewhere in the dependency tree.

v2 = actix-web-v2
v3 default = actix-web-v3

Features from optional dependencies

In crates that don't use the dep: syntax, optional dependencies automatically become Cargo features. These features may have been created by mistake, and this functionality may be removed in the future.

actix-web-v2 v2?

Enables actix-web ^2

actix-web-v3 v3

Enables actix-web ^3