sentinel pointers and c strings

README.md

@@ -51,6 +51,17 @@ Bodyless manual and imported C functions may be variadic:
 log_values :: c_func(tag c_int, ...) c_int
 ```
 
+Zero-terminated byte strings can be passed directly to immutable C character
+pointers without making `u8` and `c_char` generally interchangeable:
+
+```bro
+printf :: c_func(format *c_char, ...) c_int
+
+main :: func() void {
+	_ = printf("answer: %d\n", 42)
+}
+```
+
 Arguments after `...` accept concrete scalars, pointers, and nullable pointers.
 Narrow integers are promoted to the target C `int` or `unsigned int`, and
 `f32`/`c_float` are promoted to `c_double`. Arrays, slices, structs, and other
@@ -87,8 +98,9 @@ Current prototype features:
 - Immutable `::` bindings, mutable function-local `=` bindings, and `_` sinks
 - Exact-width signed/unsigned integers, `f32`, `f64`, `isize`, `usize`, and loose integer-constrained `int`
 - Target-dependent atomic `c_*` primitive types, `c_func`, and pointer-only `c_struct`
-- Arrays, sentinel arrays, pointers, slices, sentinel slices, strings, character literals, optionals, and native structs
-- Explicit `.ptr`/`.len`, slicing, postfix pointer dereference and optional unwrap, and keyed struct literals
+- Arrays, sentinel arrays, single-item pointers, many-item pointers, sentinel many-item pointers, slices, sentinel slices, strings, character literals, optionals, and native structs
+- String literals as immutable pointers to static zero-terminated byte arrays
+- Pointer-preserving `.ptr`/`.len`, pointer-to-array indexing and slicing, postfix pointer dereference and optional unwrap, and keyed struct literals
 - Contextual integer constants and compile-time folding of addition and unary negation trees
 - Directory packages with merged declarations and file-local relative imports
 - Relative C header imports as synthetic package namespaces