const-cstr

Create static C-compatible strings from Rust string literals.

Usage

Cargo.toml:

[dependencies]
const-cstr = "0.1"

Crate root:

#[macro_use] extern crate const_cstr;

Example

 #[macro_use] extern crate const_cstr;
 // Just for the `libc::c_char` type alias.
 extern crate libc;
     
 use std::ffi::CStr;

 const_cstr! {
     HELLO_CSTR = "Hello, world!";

     // Multiple declarations can be made with one invocation.
     // GOODNIGHT_CSTR = "Goodnight, sun!";

     // But only with the same visibility:
     // pub GOODNIGHT_CSTR = "Goodnight, sun!";
     // ^~~ Error: expected identifier, found `pub` 
 }

 // Imagine this is an `extern "C"` function linked from some other lib.
 unsafe fn print_c_string(cstr: *const libc::c_char) {
     println!("{}", CStr::from_ptr(cstr).to_str().unwrap());
 }

 fn main() {
     // When just passed a literal, returns an rvalue instead.
     let goodnight_cstr = const_cstr!("Goodnight, sun!");

     unsafe {
         print_c_string(HELLO_CSTR.as_ptr());
         print_c_string(goodnight_cstr.as_ptr());
     }
 }

Prints:

Hello, world!
Goodnight, sun!

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT) at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you shall be dual licensed as above, without any additional terms or conditions.