Accessing inline array inside a struct causes compilation error (pointer decay issue)

[cjbarre]

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Description of the issue with reproduction steps

Minimal Repro:

(cpp/raw
 "typedef struct a {
    float b[3];
  } a;
  
  a make_a(void) {
    a result = { .b = {1.0f, 2.0f, 3.0f} };
    return result;
  }")

(let [a (cpp/make_a)
      b (cpp/.-b a)])

Stack trace

In file included from <<< inputs >>>:1:
input_line_4:7:23: error: expected ')'
7 | new (ret) (float[3]) (&((a)obj)->b);
| ^
input_line_4:7:14: note: to match this '('
7 | new (ret) (float[3]) (&((a)obj)->b);
| ^
input_line_4:7:27: error: cannot initialize an array element of type 'float' with an rvalue of type
'float ()[3]'
7 | new (ret) (float[3]) (&((a*)obj)->b);
| ^~~~~~~~~~~~~
TClingCallFunc::make_wrapper:Failed to compile
==== SOURCE BEGIN ====
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wformat-security"
attribute((used)) attribute((annotate("__cling__ptrcheck(off)")))
extern "C" [[gnu::always_inline]]
inline void clojure_core_G__24083([[gnu::nonnull]] void* obj, int nargs, void** args, [[gnu::nonnull]] void* ret)
{
new (ret) (float[3]) (&((a)obj)->b);
}
#pragma clang diagnostic pop
==== SOURCE END ====
zsh: segmentation fault jank run inline-pointer-decay.jank