Infer type from collections and maps when type annotation not specified #196
Description
Example:
class Args {
@Option(names = "-o")
List<Integer> options;
@Option(name = "-P")
Map<TimeUnit, Long> duration;
@Parameters
List<URL> urls;
}
None of these fields have the type attribute specified. Picocli can infer the type from the generic type:
Field optionsField = Test.class.getDeclaredField("options");
ParameterizedType optionListType = (ParameterizedType) optionsField.getGenericType();
Class<?> cls = (Class<?>) optionListType.getActualTypeArguments()[0];
System.out.println(cls); // class java.lang.Integer