Type Alias IcuFormatterSupportPolicy 

pub type IcuFormatterSupportPolicy = fn(&IcuFormatter) -> IcuFormatterSupport;

Available on crate feature catalog only.

Callback used to validate runtime support for ICU formatters.

The callback receives each formatter discovered in a final runtime ICU message and returns whether that runtime supports the formatter kind and style.

This is intentionally a non-capturing function pointer so ICU options stay cheap to copy.