C / C + +

缺乏完整的SWAP功能 模板的语法 你不能#define一个#define(没有多通道) 编译器之间的结构打包不兼容 Char是有符号的还是无符号的?

Java

边缘上的不变性 没有像c#一样的ref关键字 到处尝试/捕捉积木 运行时性能差 所有与字符串相关的东西

Python

没有“main”(我已经习惯了!) 强调关键词 有限的线程支持 用self代替this 缺少类似C/ c++的语法

Python:

处理数字太慢了。这不是什么大问题，除非…… 不能简单地在程序中包含导入时自动编译的C代码。 在py3k接管之前，我们仍然要忍受愚蠢的整数除法规则。 在py3k接管之前，像imap和izip这样的好东西仍然存在于一个单独的模块中。 在py3k接管之前，我们还有很多工作要做。

Objective Caml

缺少名称空间。 啰嗦类和对象注释。 复杂的构建系统。 不方便制作中缀。

Python:

没有分隔符表示块的结束会导致歧义，这样自动缩进就不能处理格式不佳的代码。 没有宏(修饰符不算) 没有像haskell的cabal或perl的CPAN那样的库自动获取 不能声明变量const(是的，可以自己定义变量，但是…) 元编程被削弱 差点忘了全局解释器锁

C#

它是一种很棒的语言，特别是在LINQ中，但是与c++相比泛型支持较差。它有如此多的潜力，但目前的实现只对强类型集合和类似的琐碎事情有用。下面举几个例子:

A generic argument cannot be restricted to enums (only classes or structs). A generic argument cannot be a static class. Why? This seems like a completely artifical restriction. You cannot specify that a generic type must have a constructor with a certain signature because you cannot have constructors on interfaces. Why not? It's just another method with the special name ".ctor". Similarly, you cannot specify that a generic type must have a static method, because those also cannot be declared on interface. Something like static T Parse(string s) would often come in useful. The compiler is too eager in prohibiting some casts which the programmer knows would actually work, so they require uglyness like (TheRealType)(object)value No covariance, eg. IList<string> cannot be converted to IList<object>, even though string[] can be converted to object[]. (Microsoft might be fixing this in C# 4.0, though.)

C++

The inconsistencies in the libraries related to char* and std::string. All C++ libs should take std::strings. Characters are not bytes with respect to iostream. I do a lot of byte-oriented work. Having a "byte" type and a "character" type would significantly make it simpler. That, too, would permit scaling to Unicode somewhat easier. Bit operations should be easy on a value. I should be able to access and set the n'th bit of a value without playing AND/OR dancing. The lack of a standardized interface for GUIs. This is where Microsoft has really been able to position themselves well with C#. A standard interface binding that OS makers provide would go really far for my work.