Added ex C style Cast - important to recognize (#27371)

Additional note on how C-style casts are not recommended. Important for people to recognize when they come across, and modify if they wish.

guide/english/cplusplus/casting/index.md

@@ -70,12 +70,20 @@ void staticCastTest(float floatVal) {
     std::cout << intVal << std::endl;
 }
 
+//not recommended but important to recognize
+void cStyleCastTest(float floatVal) {
+    // Convert the float into a double.
+    auto doubleVal = (double)(floatVal);
+    std::cout << doubleVal << std::endl;
+}
+
 int main() {
     MyClassChild myClass;
     reinterpretCastTest(&myClass);
     constCastTest(myClass);
     dynamicCastTest(&myClass);
     staticCastTest(10.5);
+    cStyleCastTest(11.9);
     
     return 0;
 }