Remove cstr macro

src/buffer.rs

@@ -279,7 +279,7 @@ impl PyBuffer {
     #[inline]
     pub fn format(&self) -> &CStr {
         if self.0.format.is_null() {
-            cstr!("B")
+            CStr::from_bytes_with_nul("B".as_bytes()).unwrap()
         } else {
             unsafe { CStr::from_ptr(self.0.format) }
         }

src/exceptions.rs

@@ -340,10 +340,10 @@ impl UnicodeDecodeError {
         let pos = err.valid_up_to();
         UnicodeDecodeError::new_err(
             py,
-            cstr!("utf-8"),
+            CStr::from_bytes_with_nul("utf-8".as_bytes()).unwrap(),
             input,
             pos..pos + 1,
-            cstr!("invalid utf-8"),
+            CStr::from_bytes_with_nul("invalid utf-8".as_bytes()).unwrap(),
         )
     }
 }

src/lib.rs

@@ -147,19 +147,10 @@ mod ffi2;
 #[cfg(Py_3)]
 mod ffi3;
 
-pub mod class;
-
-/// Constructs a `&'static CStr` literal.
-macro_rules! cstr {
-    ($s: tt) => {
-        // TODO: verify that $s is a string literal without nuls
-        unsafe { ::std::ffi::CStr::from_ptr(concat!($s, "\0").as_ptr() as *const _) }
-    };
-}
-
 pub mod buffer;
 #[doc(hidden)]
 pub mod callback;
+pub mod class;
 mod conversion;
 #[doc(hidden)]
 pub mod derive_utils;