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

BrainF * ck

你的亮点是图灵完备?!我可以在Perl正则表达式中做更多的事情! 缺少对象。来吧,人!就像，你好… 没有网络库。我只想刮一个网页，天哪。 没有一级函数。恭喜你——你可以同情你的Java朋友了。 一个无限的磁带存储，没有其他。这是如此的矫情，我们可能还在写Lisp。

C#

Reference types are nullable by default; in-language null keyword is untyped. Lack of discriminated unions Exceptions as default, non-exceptional error handling method - there's not much of an alternative. archaic switch statement syntax and limitations Needless distinction between constructors + static methods Static methods can't be part of an interface Lack of by-shape interface implementation rather than explicit interface implementation - leading to numerous language design hacks such as the linq query syntax, foreach, collection & object initializers -- none of which can be flexibly reused. For example, the object initializer syntax may be nice, but plays poorly with immutable objects. Cannot inherit "interface" of a class independently of implementation - leading to code duplications and overarchitected code that provides interfaces, abstract base classes, a few common implementations, and no way to pick and choose the bits of each to use. Also; leads to too many code that's tightly coupled to a particular implementation since it's common to explicitly refer to the implementation type rather than an interface. Cannot multiply inherit via composition since a classes "interface" is tightly coupled to it's implementation; effectively lack of mixins. The above limitations of interfaces lead to a proliferation of virtually identical interfaces that don't overlap naturally in any kind of type hierarchy. IComparable vs. IEquatable vs. IComparable<T> vs object.Equals vs. operator == etc. etc. By extension, making a custom type that satisfies all these things is a lot more work than necessary (in particular for collection classes). Obviously, the language designers realize this, hence the various workarounds for things like linq, foreach and collection initializers which work by-shape rather than by-interface. Redundant use of parentheses and braces rather than layout-is-structure. Return values can be ignored, limiting the effectiveness of type inference. Enums aren't a normal type and can't have methods. Also, enum values aren't typesafe and may be initialized to 0 despite not having a 0 value. Mixing metaphors by lumping flag and non-flag enums together. Lack of proper value type support. Value types can't be inherited, have different constructor semantics, and perform poorly due to CLR limitations. Also, confusing semantics regarding value types: some values are really values (and can't be modified), and others are really non-aliased, non-null references (variables). This gets particularly confusing with regards to the next issue: Semantic distinction between fields and properties, particularly in conjunction with lack of mutability modifier (ala C++'s const) Can't specialize generics Cannot provide default generic type parameters (e.g. factory generics) lack of typedef makes generics a pain to use (using is a limited but good-to-know substitute!) Can't genericize over things other than types (e.g. functions, plain values, or names). This means you can't do something like make a generic implementation of a dependancy property leading to, well, nasty implementations of things like dependancy properties and the overuse of code-snippets and poorly readable code as a result. Limited capability to specify generic type requirements e.g. generic sum method that takes both int, double and a bigint (without tricky and often slow hacks). An interface method implementation or virtual method override cannot return a more specific type or accept a more general type; i.e. limited co/contravariance support even in C# 4.

Java

已检查的异常 类型擦除 缺少操作符重载(例如BigInteger/BigDecimal) 缺少regexp/date/duration /复杂文字 对不可变性的支持很差

Python

No statements in lambdas. GRRRR foo( a for b in c if d ) feels wrong, it surprises me every time I get away with it. Shouldin't it be foo( (a for b in c if d) )? Can i have a dict comprehension? map and filter operators have special syntax in list comprehensions, how about something for reduce? or sort? Just by having a yield statement in it, a function is magically transformed into a generator, and its interface changes completely. Also, that generator cannot do any work before the first next(). at least, not without using a function that returns a generator.

JavaScript

No brief syntax for making modular code libraries. You have to call a function that returns a dictionary of public methods. And you have to edit that in (at least) two places every time you alter the interface of your module. Creating closures involves returning it from a function that returns a function from ('sup dog) yo' function. Clutter! for each ( foo ) syntax and behavior feels like an afterthought. Knowing when your code will actually run (and in what order) is more of a dark-art. The only way to get it right for sure is put everything (yes, that too) in one big file. and even then you still need to wait for a document.onload Am i missing something? is there no trivial way to get json serialized values without building them by hand? (yes jQuery can do this, sort of).

C#

Cannot create a reference (var &t = struct) No local scope destructors (IDispose comes close but its not the same) ToString, i almost dislike that every object has it but it turns out i dislike everything using it like string.format does. I rather have things that accepts a certain type (like ints, floats, text, chars only). So instead of passing in any object i need to pass in something with a implicit typecast or interface. I ended up writing something like this to safely escape text for html which worked great. Cannot use a virtual typecast (blah)obj; does not work if obj does not inherit/has an interface of blah. Simple workaround is to supply an interface with a convert function. Has no local creation. Instead of writing var o = new Item(); i would like to write (something like) Item o() (with an automatic dispose if it has one).