Cargo Features

ryu has no features set by default.

ryu = { version = "1.0.17", features = ["small", "no-panic"] }

Use smaller lookup tables. Instead of storing every required power of 5, only store every 26th entry, and compute intermediate values with a
multiplication. This reduces the lookup table size by about 10x (only one case, and only f64) at the cost of some performance.

Features from optional dependencies

no-panic implicit feature

Enables no-panic


Attribute macro to require that the compiler prove a function can't ever panic