Perl 5:

All the really good stuff nowadays seems to require mod_perl, which has low availability everywhere I want to go. Some really incredible functionality can be encapsulated in modules, but what is under the hood is often fragile or frightening: source filters, typeglobs, whatever Moose is doing... DateTime is brilliant but still made some very bad design decisions (not returning a stopwatch duration when subtracting two DateTime objects) Dual-lifed modules in core and on CPAN still cause conflicts module authors still put interactive stuff in their module configuration scripts so that they can't be automatically installed

.NET框架(库)

嵌套类型很少使用(例如MessageBoxButton应该是MessageBox.Button) 可变结构体(Rect, Point) 系统名称空间中有太多东西 太多不同的平等概念(对象。等于,对象。ReferenceEquals, operator ==， operator !=， IComparable.CompareTo() == 0) 数组的成员是可变的，但长度是不变的。

还有一点:

XmlSerialization不适用于不可变类型

c# / .net:

Classes should be sealed by default There should be no lock statement - instead, you should have specific locking objects, and there should be methods such as Acquire which return disposable lock tokens. Corollary: there shouldn't be a monitor for every object. GetHashCode() and Equals() shouldn't be in System.Object - not everything's suitable for hashing. Instead, have an IdentityComparer which does the same thing, and keep the IComparer<T>, IComparable<T>, IEqualityComparer<T> and IEquatable<T> interfaces for custom comparisons. Poor support for immutability Poor way of discovering extension methods - it should be a much more conscious decision than just the fact that I'm using a namespace.

这些都是我想出来的，明天问我，我会想出一个不同的5个:)

C++

(除了lambda函数，我已经避免了Cpp0X中可用的东西)

不强制使用"this"访问成员变量，::GlobalFunction访问全局命名空间。 (更具体地说，算法中缺少lambda函数，将在0x thou中修复)中的所有内容 处理依赖文件/头文件和源文件 基本数据类型上的愚蠢名称(应该命名为uint8, int16等) const_cast功能

关于c#:

I hate that there is no keyword to specify which exceptions are thrown from a method like in java. Its a much better way to document exceptions than using an XML comment. I would also want a much better syntax for generic constraints like oring and anding of constraints. Why a method can't return more than one value? Lack of support for aspect oriented programming in the language. Why can't you annotate each one of the property accessors with an attribute? Lack of builtin regexp support like in perl.

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。