stack_cstr

stack_cstr is a high-performance Rust library for creating C-compatible strings (&CStr) efficiently. It uses a stack buffer for short strings to avoid heap allocation, and automatically falls back to heap allocation for longer strings. The resulting strings are safe to pass to FFI functions.

Features

• Stack buffer allocation for short strings (default 128 bytes)
• Automatic heap fallback for longer strings
• Supports format_args! style formatting
• Returns CArrayString<128> for easy FFI usage
• Simple macro interface: cstr!()
• Ergonomic and safe for passing to C APIs

Usage Example

use std::ffi::CStr;

use stack_cstr::cstr;

// Create a C-compatible string
let s = cstr!("Pi = {:.2}", 3.14159);
assert_eq!(s.as_c_str().to_str().unwrap(), "Pi = 3.14");

unsafe {
    // Pass to FFI as *const c_char
    let ptr = s.as_ptr();
    assert_eq!(CStr::from_ptr(ptr).to_str().unwrap(), "Pi = 3.14");
}