已锁定。该问题及其答案被锁定,因为该问题是题外话,但具有历史意义。它目前不接受新的答案或互动。 与同事讨论了在C#3中使用'var'关键字后,我想知道人们对于通过var进行类型推断的适当用法有何看法? 例如,我宁愿在可疑的情况下懒惰地使用var,例如: foreach(var item in someList) { // ... } // Type of 'item' not clear. var something = someObject.SomeProperty; // Type of 'something' not clear. var something = someMethod(); // Type of 'something' not clear. var的更多合法用法如下: var l = new List<string>(); // Obvious what l will be. var …
对于上下文,它位于具有防火墙的远程服务器上。我正在通过代理设置环境。我有ruby 1.8.7。当我尝试gem install .. sudo gem install --http-proxy <host address>:<port> json 我收到以下错误: Building native extensions. This could take a while... ERROR: Error installing json: ERROR: Failed to build gem native extension. /usr/bin/ruby extconf.rb mkmf.rb can't find header files for ruby at /usr/lib/ruby/ruby.h Gem files will remain installed in /usr/lib64/ruby/gems/1.8/gems/json-1.8.1 for …