# Introduction
**[`bindgen`](https://github.com/servo/rust-bindgen) automatically generates Rust
FFI bindings to C and C++ libraries.**
For example, given the C header `cool.h`:
```c
typedef struct CoolStruct {
int x;
int y;
} CoolStruct;
void cool_function(int i, char c, CoolStruct* cs);
```
`bindgen` produces Rust FFI code allowing you to call into the `cool` library's
functions and use its types:
```rust
/* automatically generated by rust-bindgen */
#[repr(C)]
pub struct CoolStruct {
pub x: ::std::os::raw::c_int,
pub y: ::std::os::raw::c_int,
}
extern "C" {
pub fn cool_function(i: ::std::os::raw::c_int,
c: ::std::os::raw::c_char,
cs: *mut CoolStruct);
}
```