# constant-cstr
[](https://crates.io/crates/constant-cstr)
[](https://docs.rs/constant-cstr)
### Create const instances of CStr at compile time
`constant-cstr` exists to enable the safe creation of
[`CStr`](https://doc.rust-lang.org/stable/core/ffi/struct.CStr.html) instances
at compile time, enabling safer and more efficient FFI. Its only exported
macro, `cstr`, statically checks its input for the presence of null bytes,
avoiding the penalty of runtime verification.