Note that the error messages must go to STD: : cerr and not STD: : cout.
注意，错误消息必须发送到std： cerr而不是std： cout。
2
When you check whether help is the relevant command option for the program (this is what vmap.count (" help ") does), the options object is dumped to cout.
当您检查help是否为程序的恰当命令行选项(这是vmap . count (“ help ”)所做的工作)时，options对象将被转储到cout。
3
Next, add the following lines in the code for the second process (Listing 4) just after STD: : cout, and rebuild the code.