Function ruma_serde::deserialize_cow_str

pub fn deserialize_cow_str<'de, D>(
    deserializer: D
) -> Result<Cow<'de, str>, D::Error> where
    D: Deserializer<'de>, 

Deserialize a Cow<'de, str>.

Different from serde’s implementation of Deserialize for Cow since it borrows from the input when possible.

This will become unnecessary if Rust gains lifetime specialization at some point; see https://github.com/serde-rs/serde/issues/1497#issuecomment-716246686.