# [ macro_export ] macro_rules ! t { ( "key.test" , $ lang : expr ) => { match $ lang . as_ref ( ) { "fr" => "C'est un test" , "en" => "This is a test" , e => panic ! ( "Missing language: {}" , e ) } } ; ( $ key : expr , $ lang : expr ) => { compile_error ! ( "Missing translation" ) ; } }