Fix Issue 19562 - core.internal.hash.hashOf array of pointers or delegates should be @safe

Author: n8sh

src/core/internal/convert.d

@@ -705,6 +705,20 @@ nothrow pure @safe unittest
     enum ctfe_works = (() => { Month x = Month.jan; return toUbyte(x).length > 0; })();
 }
 
+@trusted pure nothrow @nogc
+const(ubyte)[] toUbyte(T)(const ref T val) if (is(T == delegate) || is(T : V*, V) && __traits(getAliasThis, T).length == 0)
+{
+    if (__ctfe)
+    {
+        if (val !is null) assert(0, "Unable to compute byte representation of non-null pointer at compile time");
+        return ctfe_alloc(T.sizeof);
+    }
+    else
+    {
+        return (cast(const(ubyte)*)&val)[0 .. T.sizeof];
+    }
+}
+
 package(core.internal) bool isNonReference(T)()
 {
     static if (is(T == struct) || is(T == union))

test/hash/src/test_hash.d

@@ -1,6 +1,6 @@
 void main()
 {
-    hashOfVoidPtrArray();
+    issue19562();
     issue15111();
     issues16654And16764();
     issue18918();
@@ -15,11 +15,15 @@ void main()
     pr2243();
 }
 
-/// Check that `hashOf` can be called on an array of void pointers.
-void hashOfVoidPtrArray() @nogc nothrow pure @system
+/// Check hashOf an array of void pointers or delegates is @safe.
+void issue19562() @nogc nothrow pure @safe
 {
-    void*[] val;
-    const _ = hashOf(val); // Check a PR doesn't break this.
+    void*[10] val;
+    size_t h = hashOf(val[]);
+
+    alias D = void delegate();
+    D[10] ds;
+    h = hashOf(ds[]);
 }
 
 /// hashOf was failing for structs that had an `alias this` to a dynamic array.