feat: infer complete ptrcast target types

2026-09-20 00:01:13 +02:00
parent 5dac5baa05
commit 7f7de7a8d2
11 changed files with 122 additions and 65 deletions
@@ -35,7 +35,7 @@ roadmap and milestone history.
 - arrays `[N]T`, inferred-count arrays `[_]T`, sentinel arrays `[N;S]T`, compile-time expression array counts, slices `[]T` / `[;S]T`, single-item pointers `@T`, many-item pointers `*T`, and sentinel many-item pointers `[*;S]T`
 - pointer mutability via `mut`, optional pointers as nullable pointers, pointer arithmetic for many-item pointers, postfix dereference `^`, and trapping optional unwrap `?`
 - pointer-to-array `.len`, indexing, slicing, `.ptr` on slices and pointers-to-arrays, implicit address-taking for array-variable slices, and pointer/slice sentinel weakening
- `ptrcast!(T, ptr)` as a first-pass pointer-child retype that preserves optionality, pointer kind, mutability, and sentinel shape
+- `ptrcast!(ptr)` infers its complete pointer result from context; `ptrcast!(P, ptr)` supplies `P` explicitly; both change the child type, then permit only ordinary implicit pointer conversions to the requested target
 - unsafe `constcast!(value)` for restoring mutability to pointers, optional pointers, and slices without changing their child type or shape
 - UTF-8 string literals as immutable pointers to static zero-terminated byte arrays, supporting `\\`, `\"`, `\n`, `\r`, `\t`, `\0`, and `\xNN` escapes, plus raw backtick multiline strings
 - narrow immutable zero-terminated byte pointer/slice conversion to `*c_char` / `?*c_char` without general `u8`/`c_char` interchange
@@ -289,7 +289,7 @@ exactly once. Bare functions named `memcopy` or `memset` remain ordinary user fu
 - non-plain C record layouts such as bitfields, packed records, flexible arrays, qualified fields, and C variadic record arguments
 - arenas, pools, build-mode heap policy, and escaping-allocation diagnostics
 - recursive type factories, reflection payloads beyond records/enums, and type-producing unions/enums
- broader Zig-style pointer/result casts beyond V1 `ptrcast!(T, ptr)`
+- pointer-shape-changing casts beyond the safe implicit conversions accepted by `ptrcast!`
 - sum-type ABI/layout polish, including dynamic tag-width shrinking, all-void channel collapse, and cross-module global-id determinism
 - backed/C enum composition and must-consume fallible linting
 - result-to-argument type-demand propagation through function call boundaries