Cargo Features

[dependencies]
synstructure = { version = "0.13.1", default-features = false, features = ["proc-macro"] }
default = proc-macro

The proc-macro feature is set by default whenever synstructure is added without default-features = false somewhere in the dependency tree.

proc-macro default

Enables proc-macro of proc-macro2, quote, and syn

quote:

Disabling the proc-macro feature removes the dynamic library dependency on libproc_macro in the rustc compiler.

Affects synstructure::MacroResult.into_stream