我刚刚发现，在c#中创建泛型方法时，我不能使用Enum作为类型约束。

微软有一个足够好的解释，但仍然。我疯了

public static T MyFunc<T>(string arg) where T:Enum //wont work :(

JavaScript

Every script is executed in a single global 'namespace'...something which you have to look out for when working with scripts from different sources If a variable is used but hasnt been defined before hand, it is considered a global variable Browser vendors making up standards as they please, making coding for us developers using such a beautiful language harder than it should be Case-Sensitivity - considering that there is no decent IDE for developing js with compile-time checking Workarounds (such as the use of hasOwnProperty method) to perform some, otherwise simple operations.

objective - c

1)没有命名空间，只有手动命名约定——我不介意在类分离方面，但我确实怀念能够在一行命名空间中导入所有类定义(如import com.me.somelibrary.*)。

2)库在像RegEx支持这样的重要领域仍然存在一些漏洞。

3)属性语法有点笨拙，需要三行(在两个单独的文件中)来声明一个属性。

4)我喜欢保留/释放模式，但它比应该的更容易释放一个引用，然后意外地使用它。

5)虽然不是真正的语言特性，但Xcode与Objective-C的使用是如此交织在一起，我不禁想到这方面……基本上自动补全，是很可疑的。它更像是一个奖励你找到你想要的东西的系统，然后把它作为一个选择。但我想我从来都不喜欢自动补全引擎。

F#

Type inference is limited. It propagates forward only. F# won't try to infer an object type based on the methods and properties used: you'll get "lookup of indeterminate object type" errors when it doesn't have a clue. One cannot mix floats and ints: 1 + 2.3 is a type error. It's a little awkward to have to create a builder object in order to define a monad or computation expression. In Haskell or Scala, you can define the monad operations directly on the monadic object. Though the #light syntax is preferred, the indentation rules are sometimes not very intuitive or become cumbersome.

Python:

速度 静态分析(缺乏) 匿名函数仅限于一个表达式

我使用Java，我最大的不满是字符串操作的低效率。当你使用+运算符时。说真的，难道编译器不能计算出我添加了多少字符串，然后在后台为我生成StringBuffer的东西吗?

通常，使用+的代码比StringBuffers操作序列更具可读性。

另外，我讨厌本机数组和集合框架之间的冗余。. toarray()的语法极其丑陋。