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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.
use std::c_str::CString;
use std::libc::{c_char, c_int};
extern {
fn sprintf(s: *mut c_char, format: *c_char, ...) -> c_int;
}
unsafe fn check<T>(expected: &str, f: |*mut c_char| -> T) {
let mut x = [0i8, ..50];
f(&mut x[0] as *mut c_char);
let res = CString::new(&x[0], false);
assert_eq!(expected, res.as_str().unwrap());
}
pub fn main() {
unsafe {
// Call with just the named parameter
"Hello World\n".with_c_str(|c| {
check("Hello World\n", |s| sprintf(s, c));
});
// Call with variable number of arguments
"%d %f %c %s\n".with_c_str(|c| {
check("42 42.500000 a %d %f %c %s\n\n", |s| {
sprintf(s, c, 42i, 42.5f64, 'a' as c_int, c);
})
});
// Make a function pointer
let x: extern "C" unsafe fn(*mut c_char, *c_char, ...) -> c_int = sprintf;
// A function that takes a function pointer
unsafe fn call(p: extern "C" unsafe fn(*mut c_char, *c_char, ...) -> c_int) {
// Call with just the named parameter via fn pointer
"Hello World\n".with_c_str(|c| {
check("Hello World\n", |s| p(s, c));
});
// Call with variable number of arguments
"%d %f %c %s\n".with_c_str(|c| {
check("42 42.500000 a %d %f %c %s\n\n", |s| {
p(s, c, 42i, 42.5f64, 'a' as c_int, c);
})
});
}
// Pass sprintf directly
call(sprintf);
// Pass sprintf indirectly
call(x);
}
}
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