Rust: generate <integer>::from_str_radix for non-base-10 .to_i conver…

…sions

shared/src/main/scala/io/kaitai/struct/translators/RustTranslator.scala

@@ -54,13 +54,17 @@ class RustTranslator(provider: TypeProvider, config: RuntimeConfig) extends Base
   override def strConcat(left: expr, right: expr, extPrec: Int) =
     "format!(\"{}{}\", " + translate(left) + ", " + translate(right) + ")"
 
-  override def strToInt(s: expr, base: expr): String =
-    translate(base) match {
+  // TODO: do not generate .unwrap(), generate ? instead
+  override def strToInt(s: expr, base: expr): String = {
+    val baseStr = translate(base)
+    baseStr match {
       case "10" =>
         s"${translate(s)}.parse().unwrap()"
       case _ =>
-        "panic!(\"Converting from string to int in base {} is unimplemented\", " + translate(base) + ")"
+        // TODO: Would be better to add a method to runtime which would be able to deduce returning type
+        s"i64::from_str_radix(${translate(s)}, $baseStr).unwrap()"
     }
+  }
 
   override def enumToInt(v: expr, et: EnumType): String =
     translate(v)