unsafe上下文提供的另一个新类型是不安全函数(unsafe functions)。 不安全函数和常规的函数/方法没多大差别,不过它们并不安全,需要用不安全关键字unsafe定义。 既然定义是不安全的,那使用起来自然就得用unsafe {}包裹才行。 直接来看下例子 fnmain(){unsafefndangerous(){}unsafe{
不安全函数定义时前面也需要加unsafe关键字,意味着函数中有不安全的操作: unsafefndangerous()->i32{letmutnum=5;letr=&numas*consti32;return*r}dangerous();// 报错,不允许unsafe块外部调用不安全函数// 在unsafe块中调用unsafe{letnum=dangerous();println!("{}",num);// 5} 创建不安全代码的安全抽象 ...
pub fnsay_hello(message: &str){let name = CString::new(message).expect("CString::new failed");unsafe {c_say_hello(name.as_ptr);// Call the C function}} 最后,可以在程序中调用包装 C 代码的“安全” Rust 函数: use sanitizers::say_hello; fnmain{say_hello("This is far too long and...
AI代码解释 // ffi/rust-call-c/src/main.rs// 标准库<stdlib.h>内置的abs函数extern"C"{#[link_name="abs"]fnabs_in_rust(input:i32)->i32;}fnmain(){unsafe{println!("abs(-1) is {}",abs_in_rust(-1));}} 2. 标准库 在实际开发 Rust 语言与其它语言相互调用的程序时,会遇到需要相互传...
Unsafe-Call External Code 比如从c的FFI(Foreign Function Interface)中调用函数,当然,程序员要负责对应的c library正确。 1 2 3 4 5 6 7 8 9 extern"C"{ fn abs(input: i32) -> i32; } fn main() { unsafe{ println!("Absolute value of -3 according to C: {}", abs(-3)); ...
//extern 的使用无需 unsafe#[no_mangle]pubextern"C"fncall_from_c() {println!("Just called a Rust function from C!");} 访问或修改可变静态变量# 全局变量在 Rust 中被称为静态(static)变量,一个拥有字符串 slice 值的静态变量的声明和应用: ...
// Don't call `drop` -- the waker will be consumed by `wake`.crate::mem::forget(self);// SAFETY: This is safe because `Waker::from_raw` is the only way// to initialize `wake` and `data` requiring the user to acknowledge// that the contract of `RawWaker` is upheld.unsafe{(...
#[no_mangle]pubextern"C"fncall_from_c(){println!("called a rust function from C");}fnmain(){} 1. 2. 3. 4. 5. 6. 7. 8. staticmutCOUNTER:u32=0;fnadd_to_count(inc:u32){unsafe{COUNTER+=inc;}}fnmain(){add_to_count(3);unsafe{println!("COUNTER:{}",COUNTER);}} ...
Unsafe-Call External Code 比如从c的FFI(Foreign Function Interface)中调用函数,当然,程序员要负责对应的c library正确。 extern "C" { fn abs(input: i32) -> i32; } fn main() { unsafe { println!("Absolute value of -3 according to C: {}", abs(-3)); ...
> The Rustonomicon digs into all the awful details that you need to understand when writing Unsafe Rust programs. 在Rustonomicon 中,首先回答了一个问题: Q:为什么我们前面没有讨论函数体(function body)中的 lifetimes? A:不需要。Rust编译器能够很好的处理 lifetimes in local context。当跨越函数的边界...