pub const fn Class(value: &'static str) -> Class
Expand description
Class code constant constructor
Can be used to define constant values for Class
from string literals.
Use Class::from_str()
for non-literals.
§Panics
Panics if the passed string is not a valid class code.
§Examples
const MY_ERROR_CLASS: Class = Class("XR");
let sqlstate = some_db_query_function(..);
match sqlstate.class() {
MY_ERROR_CLASS => println!("got an error in my expected class"),
_ => panic!("unexpected condition")
}
An invalid class code in a constant context will cause a compile time panic:
ⓘ
const MY_ERROR_CLASS: Class = Class("!R"); // error: evaluation of constant value failed
but an invalid class code in a non-constant context may only panic at runtime:
ⓘ
let some_class = Class("!R"); // panics