CString and NulError are in alloc.

Author: sunfishcode

build.rs

@@ -18,6 +18,7 @@ fn main() {
     {
         use_feature_or_nothing("const_raw_ptr_deref");
         use_feature_or_nothing("core_c_str");
+        use_feature_or_nothing("alloc_c_string");
     }
 
     // Gather target information.

src/ffi/mod.rs

@@ -1,7 +1,9 @@
 //! Utilities related to FFI bindings.
 
 #[cfg(not(feature = "std"))]
-pub use core::ffi::{CStr, CString, FromBytesWithNulError, NulError};
+pub use alloc::ffi::{CString, NulError};
+#[cfg(not(feature = "std"))]
+pub use core::ffi::{CStr, FromBytesWithNulError};
 
 #[cfg(feature = "std")]
 pub use std::ffi::{CStr, CString, FromBytesWithNulError, NulError};

src/lib.rs

@@ -103,6 +103,8 @@
 )]
 #![cfg_attr(io_lifetimes_use_std, feature(io_safety))]
 #![cfg_attr(core_c_str, feature(core_c_str))]
+#![cfg_attr(alloc_c_string, feature(alloc_ffi))]
+#![cfg_attr(alloc_c_string, feature(alloc_c_string))]
 #![cfg_attr(not(feature = "std"), no_std)]
 #![cfg_attr(feature = "rustc-dep-of-std", feature(core_intrinsics))]
 #![cfg_attr(feature = "rustc-dep-of-std", feature(ip))]