move compile time convertImpl to compiletile helpers

stint/private/compiletime_helpers.nim

@@ -1,5 +1,20 @@
 import ./datatypes, ./uint_bitwise_ops
 
+func convertImpl[T: SomeInteger](x: SomeInteger): T {.compileTime.} =
+  cast[T](x)
+
+func convertImpl[T: IntImpl|UintImpl](x: IntImpl|UintImpl): T {.compileTime.} =
+  result.hi = convertImpl[type(result.hi)](x.hi)
+  result.lo = x.lo
+
+template convert*[T](x: UintImpl|IntImpl|SomeInteger): T =
+  when nimvm:
+    # this is a workaround Nim VM inability to cast
+    # something non integer
+    convertImpl[T](x)
+  else:
+    cast[T](x)
+    
 func getByte*(x: SomeInteger, pos: int): byte {.compileTime.} =
   type DT = type x
   byte((x shr (pos * 8)) and 0xFF.DT)

stint/private/endians2_priv.nim

@@ -8,7 +8,7 @@ func swapBytes*(x: UintImpl): UintImpl {.inline.} =
 
   UintImpl(hi: hi, lo: lo)
 
-func copyMem(x: UintImpl, ret: var openArray[byte]) {.compileTime.} =
+func copyMem*(x: UintImpl, ret: var openArray[byte]) {.compileTime.} =
   const size = bitsof(x) div 8
   type DT = type x.leastSignificantWord
   for i in 0 ..< size:

stint/private/int_bitwise_ops.nim

@@ -7,7 +7,7 @@
 #
 # at your option. This file may not be copied, modified, or distributed except according to those terms.
 
-import  ./datatypes, ./bitops2_priv, ./uint_bitwise_ops
+import  ./datatypes, ./bitops2_priv, ./uint_bitwise_ops, ./compiletime_helpers
 
 func `not`*(x: IntImpl): IntImpl {.inline.}=
   ## Bitwise complement of unsigned integer x
@@ -25,21 +25,6 @@ func `xor`*(x, y: IntImpl): IntImpl {.inline.}=
   ## `Bitwise xor` of numbers x and y
   applyHiLo(x, y, `xor`)
 
-func convertImpl[T: SomeInteger](x: SomeInteger): T {.compileTime.} =
-  cast[T](x)
-
-func convertImpl[T: IntImpl|UintImpl](x: IntImpl|UintImpl): T {.compileTime.} =
-  result.hi = convertImpl[type(result.hi)](x.hi)
-  result.lo = x.lo
-
-template convert[T](x: UintImpl|IntImpl|SomeInteger): T =
-  when nimvm:
-    # this is a workaround Nim VM inability to cast
-    # something non integer
-    convertImpl[T](x)
-  else:
-    cast[T](x)
-
 func `shl`*(x: IntImpl, y: SomeInteger): IntImpl {.inline.}=
   ## Compute the `shift left` operation of x and y
   # Note: inlining this poses codegen/aliasing issue when doing `x = x shl 1`