fn main() { // bad arguments to the format! call // bad number of arguments, see #44954 (originally #15780) format!("{}"); //~^ ERROR: 1 positional argument in format string, but no arguments were given format!("{1}", 1); //~^ ERROR: invalid reference to positional argument 1 (there is 1 argument) //~^^ ERROR: argument never used format!("{} {}"); //~^ ERROR: 2 positional arguments in format string, but no arguments were given format!("{0} {1}", 1); //~^ ERROR: invalid reference to positional argument 1 (there is 1 argument) format!("{0} {1} {2}", 1, 2); //~^ ERROR: invalid reference to positional argument 2 (there are 2 arguments) format!("{} {value} {} {}", 1, value=2); //~^ ERROR: invalid reference to positional argument 2 (there are 2 arguments) format!("{name} {value} {} {} {} {} {} {}", 0, name=1, value=2); //~^ ERROR: invalid reference to positional arguments 3, 4 and 5 (there are 3 arguments) format!("{} {foo} {} {bar} {}", 1, 2, 3); //~^ ERROR: there is no argument named `foo` //~^^ ERROR: there is no argument named `bar` format!("{foo}"); //~ ERROR: no argument named `foo` format!("", 1, 2); //~ ERROR: multiple unused formatting arguments format!("{}", 1, 2); //~ ERROR: argument never used format!("{1}", 1, 2); //~ ERROR: argument never used format!("{}", 1, foo=2); //~ ERROR: named argument never used format!("{foo}", 1, foo=2); //~ ERROR: argument never used format!("", foo=2); //~ ERROR: named argument never used format!("{} {}", 1, 2, foo=1, bar=2); //~ ERROR: multiple unused formatting arguments format!("{foo}", foo=1, foo=2); //~ ERROR: duplicate argument format!("", foo=1, 2); //~ ERROR: positional arguments cannot follow // bad named arguments, #35082 format!("{valuea} {valueb}", valuea=5, valuec=7); //~^ ERROR there is no argument named `valueb` //~^^ ERROR named argument never used // bad syntax of the format string format!("{"); //~ ERROR: expected `'}'` but string was terminated format!("foo } bar"); //~ ERROR: unmatched `}` found format!("foo }"); //~ ERROR: unmatched `}` found format!("foo %s baz", "bar"); //~ ERROR: argument never used format!(r##" {foo} "##); //~^^^ ERROR: there is no argument named `foo` // bad syntax in format string with multiple newlines, #53836 format!("first number: {} second number: {} third number: {} fourth number: {} fifth number: {} sixth number: {} seventh number: {} eighth number: {} ninth number: { tenth number: {}", 1, 2, 3, 4, 5, 6, 7, 8, 9, 10); //~^^ ERROR: invalid format string }