小编Da *_* Li的帖子

我本地安装了 postgresql。正如我所得到的，它不会启动：

psql: could not connect to server: No such file or directory
    Is the server running locally and accepting
    connections on Unix domain socket "/var/run/postgresql/.s.PGSQL.5432"?

手动启动不起作用：

sudo /etc/init.d/postgresql restart
  * Restarting PostgreSQL 9.4 database server
  * The PostgreSQL server failed to start. Please check the log output:
       2015-03-09 17:41:39 CET [3769-1] FATAL:  could not create lock file "/var/run/postgresql/.s.PGSQL.5432.lock": Permission denied

好的，权限有问题。让我们看看它们：

ls -all /var/run/
drwxr-xr-x 27 root        root         900 Mar  9 17:36 .
drwxr-xr-x 25 root        root        4096 Feb …

如何在reflect.runtime.universe.Type上进行模式匹配？

def test(t: reflect.runtime.universe.Type) {
  t match {
    case Int => \\ ...
    case Double => \\ ...
    case String => \\ ... 
    case _ =>  \\ ...
  }
}    

这不起作用,因为翻译抱怨:

error: pattern type is incompatible with expected type;
 found   : Int.type
 required: reflect.runtime.universe.Type
Note: if you intended to match against the class, try `case _: Int`
         case Int => // ...
              ^

尝试该建议也不起作用:

def test(t: reflect.runtime.universe.Type) {
  t match {
    case _: Int => \\ ...
    case _: Double …