本文API
移除元素
remove(beg, end, value)
remove_if(beg, end, op)
remove_copy(sourceBeg, sourceEnd, destBeg, value)
remove_copy_if(sourceBeg, sourceEnd, destBeg, op)
移除连续重复的元素
unique(beg, end)
unique(beg, end, op)
unique_copy(sourceBeg, sourceEnd, destBeg)
unique_copy(sourceBeg, sourceEnd, destBeg, op)