Cargo Features

[dependencies]
mbd = { version = "0.1.1", default-features = false, features = ["console_error_panic_hook", "wee_alloc"] }
default = console_error_panic_hook

The console_error_panic_hook feature is set by default whenever mbd is added without default-features = false somewhere in the dependency tree.

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.

console_error_panic_hook default

Enables console_error_panic_hook

The console_error_panic_hook crate provides better debugging of panics by logging them with console.error. This is great for development, but requires all the std::fmt and std::panicking infrastructure, so isn't great for code size when deploying.

wee_alloc implicit feature

Enables wee_alloc

wee_alloc is a tiny allocator for wasm that is only ~1K in code size compared to the default allocator's ~10K. It is slower than the default allocator, however.

Unfortunately, wee_alloc requires nightly Rust when targeting wasm for now.