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// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
#![feature(libc, std_misc)]
extern crate libc;
use std::ffi::{CStr, CString};
use libc::{c_char, c_int};
extern {
fn sprintf(s: *mut c_char, format: *const c_char, ...) -> c_int;
}
unsafe fn check<T, F>(expected: &str, f: F) where F: FnOnce(*mut c_char) -> T {
let mut x = [0 as c_char; 50];
f(&mut x[0] as *mut c_char);
assert_eq!(expected.as_bytes(), CStr::from_ptr(x.as_ptr()).to_bytes());
}
pub fn main() {
unsafe {
// Call with just the named parameter
let c = CString::new(&b"Hello World\n"[..]).unwrap();
check("Hello World\n", |s| sprintf(s, c.as_ptr()));
// Call with variable number of arguments
let c = CString::new(&b"%d %f %c %s\n"[..]).unwrap();
check("42 42.500000 a %d %f %c %s\n\n", |s| {
sprintf(s, c.as_ptr(), 42, 42.5f64, 'a' as c_int, c.as_ptr());
});
// Make a function pointer
let x: unsafe extern fn(*mut c_char, *const c_char, ...) -> c_int = sprintf;
// A function that takes a function pointer
unsafe fn call(p: unsafe extern fn(*mut c_char, *const c_char, ...) -> c_int) {
// Call with just the named parameter
let c = CString::new(&b"Hello World\n"[..]).unwrap();
check("Hello World\n", |s| sprintf(s, c.as_ptr()));
// Call with variable number of arguments
let c = CString::new(&b"%d %f %c %s\n"[..]).unwrap();
check("42 42.500000 a %d %f %c %s\n\n", |s| {
sprintf(s, c.as_ptr(), 42, 42.5f64, 'a' as c_int, c.as_ptr());
});
}
// Pass sprintf directly
call(sprintf);
// Pass sprintf indirectly
call(x);
}
}
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