pub type Namespaces = String;
#[macro_export]
macro_rules! namespaces {
( $( $prefix:ident = $uri:expr ),* $(,)? ) => {
{
let mut namespaces = String::new();
$(
namespaces.push_str(&format!(" xmlns:{}=\"{}\"", stringify!($prefix), $uri));
)*
namespaces
}
};
}