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: 3 positional arguments in format string, but there are 2 arguments format!("{name} {value} {} {} {} {} {} {}", 0, name=1, value=2); //~^ ERROR: 6 positional arguments in format string, but there are 3 arguments format!("{} {foo} {} {bar} {}", 1, 2, 3); //~^ ERROR: cannot find value `foo` in this scope //~^^ ERROR: cannot find value `bar` in this scope format!("{foo}"); //~ ERROR: cannot find value `foo` in this scope 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} {} {}", foo=1, 2); //~ ERROR: positional arguments cannot follow // bad named arguments, #35082 format!("{valuea} {valueb}", valuea=5, valuec=7); //~^ ERROR cannot find value `valueb` in this scope //~^^ 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: cannot find value `foo` in this scope // 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 println!("{} {:.*} {}", 1, 3.2, 4); //~^ ERROR 4 positional arguments in format string, but there are 3 arguments //~| ERROR mismatched types println!("{} {:07$.*} {}", 1, 3.2, 4); //~^ ERROR invalid reference to positional arguments 3 and 7 (there are 3 arguments) //~| ERROR mismatched types println!("{} {:07$} {}", 1, 3.2, 4); //~^ ERROR invalid reference to positional argument 7 (there are 3 arguments) println!("{:foo}", 1); //~ ERROR unknown format trait `foo` println!("{5} {:4$} {6:7$}", 1); //~^ ERROR invalid reference to positional arguments 4, 5, 6 and 7 (there is 1 argument) let foo = 1; println!("{foo:0$}"); //~^ ERROR invalid reference to positional argument 0 (no arguments were given) // We used to ICE here because we tried to unconditionally access the first argument, which // doesn't exist. println!("{:.*}"); //~^ ERROR 2 positional arguments in format string, but no arguments were given println!("{:.0$}"); //~^ ERROR invalid reference to positional argument 0 (no arguments were given) }