Fix issue 31

core/src/fr/hammons/slinc/Mem.scala

@@ -12,6 +12,7 @@ trait Mem:
   def writeShort(v: Short, offset: Bytes): Unit
   def writeByte(v: Byte, offset: Bytes): Unit
   def writeByteArray(v: Array[Byte], offset: Bytes): Unit
+  def writeAddress(v: Mem, offset: Bytes): Unit
 
   def writeInt(v: Int, offset: Bytes): Unit
   def writeIntArray(v: Array[Int], offset: Bytes): Unit

core/src/fr/hammons/slinc/Send.scala

@@ -173,3 +173,10 @@ object Send:
       while i < value.length do
         s.to(mem, offset + (l.layout.size * i), value(i))
         i += 1
+
+  private val ptrSend: Send[Ptr[Any]] = new Send[Ptr[Any]]:
+    def to(mem: Mem, offset: Bytes, value: Ptr[Any]): Unit = 
+      mem.writeAddress(value.mem, offset)
+
+
+  given sendPtr[A]: Send[Ptr[A]] = ptrSend.asInstanceOf[Send[Ptr[A]]]

core/test/resources/native/test.c

@@ -6,4 +6,13 @@
 
 EXPORTED int identity_int(int i) {
   return i;
+}
+
+struct I31Struct {
+  const char* field;
+
+};
+
+EXPORTED const char* i31test(struct I31Struct i31Struct) {
+  return i31Struct.field;
 }

core/test/src/fr/hammons/slinc/BindingSpec.scala

@@ -3,12 +3,24 @@ package fr.hammons.slinc
 import munit.ScalaCheckSuite
 
 trait BindingSpec(val slinc: Slinc) extends ScalaCheckSuite:
-  import slinc.{given,*}
+  import slinc.{given, *}
   @LibraryName("@test")
   object Test derives Library:
     def identity_int(i: CInt): CInt = Library.binding
+    // issue 31 test binding
+    def i31test(struct: I31Struct): Ptr[CChar] = Library.binding
+
+    case class I31Struct(field: Ptr[CChar]) derives Struct
 
   test("int_identity") {
     assertEquals(Test.identity_int(5), 5)
   }
 
+  test("issue 31 fix") {
+    Scope.confined {
+      val struct = Test.I31Struct(
+        Ptr.copy("hello world!")
+      )
+      Test.i31test(struct)
+    }
+  }

j17/src/fr/hammons/slinc/Mem17.scala

@@ -4,6 +4,7 @@ import jdk.incubator.foreign.MemorySegment
 import jdk.incubator.foreign.MemoryAccess
 import jdk.incubator.foreign.ResourceScope
 import jdk.incubator.foreign.CLinker.{C_CHAR, C_INT}
+import jdk.incubator.foreign.Addressable
 
 class Mem17(private[slinc] val mem: MemorySegment) extends Mem:
   override def readDouble(offset: Bytes): Double =
@@ -60,6 +61,9 @@ class Mem17(private[slinc] val mem: MemorySegment) extends Mem:
   override def writeShort(v: Short, offset: Bytes): Unit =
     MemoryAccess.setShortAtOffset(mem, offset.toLong, v)
 
+  override def writeAddress(v: Mem, offset: Bytes): Unit = 
+    MemoryAccess.setAddress(mem, v.asBase.asInstanceOf[Addressable])
+
   override def readByte(offset: Bytes): Byte =
     MemoryAccess.getByteAtOffset(mem, offset.toLong)
 

j19/src/fr/hammons/slinc/Mem19.scala

@@ -3,6 +3,7 @@ package fr.hammons.slinc
 import java.lang.foreign.MemorySegment
 import java.lang.foreign.MemorySession
 import java.lang.foreign.ValueLayout, ValueLayout.*
+import java.lang.foreign.Addressable
 
 object Mem19:
   val javaShort = JAVA_SHORT.nn.withBitAlignment(8)
@@ -76,6 +77,8 @@ class Mem19(private[slinc] val mem: MemorySegment) extends Mem:
   override def readShort(offset: Bytes): Short =
     mem.get(javaShort, offset.toLong)
 
+  def writeAddress(v: Mem, offset: Bytes): Unit = mem.set(javaAddress, offset.toLong, v.asBase.asInstanceOf[Addressable])
+
   override def readIntArray(offset: Bytes, size: Int): Array[Int] =
     val arr = Array.ofDim[Int](size)
     val resizedMem = resizeSegment(Bytes(size * javaInt.nn.byteSize()))