waker-fn is used at run time in 1,251 crates (of which 997 optionally, 7 directly). It's used at build time in 6 crates (of which 6 optionally, 0 directly). It's used only as a dev dependency in 338 crates (4 directly).

Depender (with downloads and own rev deps) waker-fn version
550K 42 event-listener dev ^1.0.0
527K 178 futures-lite optional ^1.0.0
462K 100 async-io ^1.1.0
91K 100 flume dev ^1.1.0
73K 77 isahc ^1
4.7K 12 async-oneshot dev ^1
1.2K 1 barrage dev ^1
500 4 xtra dev ^1.1
decurse ^1.1
uringy ^1.1.0
yield-closures ^1