Macro prefixes 

macro_rules! prefixes {
    ($($name:ident $(as $prefix:literal)?),* $(,)?) => { ... };
}

Writes the prefixes of namespaces defined by namespace!.

Every namespace has the name of its macro as prefix unless another one is given with as. The result is the table for SerializerConfig::namespaces and DeserializerConfig::namespaces:

use deser_xml::{DeserializerConfig, SerializerConfig, prefixes};

deser_xml::namespace!(
    atom = "http://www.w3.org/2005/Atom",
    dc = "http://purl.org/dc/elements/1.1/",
    xlink = "http://www.w3.org/1999/xlink",
);

const PREFIXES: &[(&str, &str)] =
    prefixes![atom as "", dc, xlink as "xl"];
assert_eq!(PREFIXES, [
    ("", "http://www.w3.org/2005/Atom"),
    ("dc", "http://purl.org/dc/elements/1.1/"),
    ("xl", "http://www.w3.org/1999/xlink"),
]);

const WRITE: SerializerConfig =
    SerializerConfig::new().namespaces(PREFIXES);
const READ: DeserializerConfig =
    DeserializerConfig::new().namespaces(PREFIXES);