/**
* Returns a copy of the given map as a {@link CharArrayMap}. If the given map is a {@link
* CharArrayMap} the ignoreCase property will be preserved.
*
* @param map a map to copy
* @return a copy of the given map as a {@link CharArrayMap}. If the given map is a {@link
* CharArrayMap} the ignoreCase property as well as the matchVersion will be of the given map
* will be preserved.
*/
@SuppressWarnings("unchecked")
public static <V> CharArrayMap<V> copy(final Map<?, ? extends V> map) {
if (map == EMPTY_MAP) return emptyMap();
if (map instanceof CharArrayMap) {
CharArrayMap<V> m = (CharArrayMap<V>) map;
// use fast path instead of iterating all values
// this is even on very small sets ~10 times faster than iterating
final char[][] keys = new char[m.keys.length][];
System.arraycopy(m.keys, 0, keys, 0, keys.length);
final V[] values = (V[]) new Object[m.values.length];
System.arraycopy(m.values, 0, values, 0, values.length);
m = new CharArrayMap<>(m);
m.keys = keys;
m.values = values;
return m;
}
// In jdk-9b54 or later, a plain diamond causes compile error with "-source 1.7":
return new CharArrayMap<V>(map, false);
}
