我是主申请人但是我的h1b快过期了(半年内),现计划5月20号结婚(520,呵呵)。 我们州拿到marriage certificate估计要一到两周,现在担心六月485会有排期。 我想求助问一下,如果我先交我的485,领导的485五月底没赶上因为没有certificate ,六月开始排期排到10月份再交她的。那么我的485如果走狗屎运批了的话,她的485会 不会不能交了? 还是有个什么follow to join的渠道,不是很懂。
g*r
3 楼
With this car Volkswagen has revolutionized the automobile industry in China . This really is revolutionary and modifies all the concepts that we've had for years that a vehicle is driven by a motor which always rolled. This car has no wheels--IT'S IN THE AIR! We know it will take some years to become popular, but the prototype works perfectly. VW-China- will produce hundreds of thousands just to supply the Chinese market. There are plans to introduce in the United States and Europe and in South America later. Click on the link, watch full screen and prepare to be amazed! http://www.flixxy.com/volkswagen-levitating-car.htm
【在 g***r 的大作中提到】 : With this car Volkswagen has revolutionized the automobile industry in China : . This really is revolutionary and modifies all the concepts that we've had : for years that a vehicle is driven by a motor which always rolled. This car : has no wheels--IT'S IN THE AIR! We know it will take some years to become : popular, but the prototype works perfectly. VW-China- will produce hundreds : of thousands just to supply the Chinese market. : There are plans to introduce in the United States and Europe and in South : America later. : Click on the link, watch full screen and prepare to be amazed! : http://www.flixxy.com/volkswagen-levitating-car.htm
【在 e****d 的大作中提到】 : Isn't it exciting? It's supposed to be finalized in this March. : Not sure when it will be adopted by industries.
s*o
13 楼
牛
China had car hundreds
【在 g***r 的大作中提到】 : With this car Volkswagen has revolutionized the automobile industry in China : . This really is revolutionary and modifies all the concepts that we've had : for years that a vehicle is driven by a motor which always rolled. This car : has no wheels--IT'S IN THE AIR! We know it will take some years to become : popular, but the prototype works perfectly. VW-China- will produce hundreds : of thousands just to supply the Chinese market. : There are plans to introduce in the United States and Europe and in South : America later. : Click on the link, watch full screen and prepare to be amazed! : http://www.flixxy.com/volkswagen-levitating-car.htm
【在 g***r 的大作中提到】 : With this car Volkswagen has revolutionized the automobile industry in China : . This really is revolutionary and modifies all the concepts that we've had : for years that a vehicle is driven by a motor which always rolled. This car : has no wheels--IT'S IN THE AIR! We know it will take some years to become : popular, but the prototype works perfectly. VW-China- will produce hundreds : of thousands just to supply the Chinese market. : There are plans to introduce in the United States and Europe and in South : America later. : Click on the link, watch full screen and prepare to be amazed! : http://www.flixxy.com/volkswagen-levitating-car.htm
【在 e****d 的大作中提到】 : Do you think reflection can be mostly implemented : using template?
j*x
33 楼
吼吼
China had car hundreds
【在 g***r 的大作中提到】 : With this car Volkswagen has revolutionized the automobile industry in China : . This really is revolutionary and modifies all the concepts that we've had : for years that a vehicle is driven by a motor which always rolled. This car : has no wheels--IT'S IN THE AIR! We know it will take some years to become : popular, but the prototype works perfectly. VW-China- will produce hundreds : of thousands just to supply the Chinese market. : There are plans to introduce in the United States and Europe and in South : America later. : Click on the link, watch full screen and prepare to be amazed! : http://www.flixxy.com/volkswagen-levitating-car.htm
I know they are not the same thing such as one for compile time while the other for runtime. But can I use template to achieve the same or similar effect of reflection.
【在 D*******a 的大作中提到】 : 不是一个概念
w*s
37 楼
这帖子是不是发早了几天。。。
China had car hundreds
【在 g***r 的大作中提到】 : With this car Volkswagen has revolutionized the automobile industry in China : . This really is revolutionary and modifies all the concepts that we've had : for years that a vehicle is driven by a motor which always rolled. This car : has no wheels--IT'S IN THE AIR! We know it will take some years to become : popular, but the prototype works perfectly. VW-China- will produce hundreds : of thousands just to supply the Chinese market. : There are plans to introduce in the United States and Europe and in South : America later. : Click on the link, watch full screen and prepare to be amazed! : http://www.flixxy.com/volkswagen-levitating-car.htm
you use RTTI to achieve reflection-like effect. template has nothing to do with it. C++ RTTI is very limited, and if you want to use that for reflection it's going to be awkward. macro is probably better.
【在 e****d 的大作中提到】 : I know they are not the same thing such as one : for compile time while the other for runtime. : But can I use template to achieve the same or : similar effect of reflection.
g*r
41 楼
怎么讲?朋友转发给我的,我就顺手转贴了
【在 w***s 的大作中提到】 : 这帖子是不是发早了几天。。。 : : China : had : car : hundreds
Template definitely can implement something similar to reflection. For each class that you want reflection enabled, use template to define a meta class for it.
【在 t****t 的大作中提到】 : you use RTTI to achieve reflection-like effect. template has nothing to do : with it. C++ RTTI is very limited, and if you want to use that for : reflection it's going to be awkward. macro is probably better.
for one thing, how do you plan to get the name of the class, or the name of the member, with template?
【在 e****d 的大作中提到】 : Template definitely can implement something similar to : reflection. : For each class that you want reflection enabled, use : template to define a meta class for it.
【在 e****d 的大作中提到】 : take a look at the struct adapter in boost::fusion.
s*o
61 楼
为啥不可行,磁悬浮啥原理?
【在 w***s 的大作中提到】 : 原理不可行
n*g
62 楼
同学们不要浮躁,有饭吃就行。管它有无前途,骗也是一门大学问,社会需要会忽悠的 人才。
s*n
63 楼
If there is such a macro system that's universally accepted and all libs can reliably depend on it, it is effectively a radical change to language itself. Achieving such a macro system is no less difficult than having reflection built in.
【在 e****d 的大作中提到】 : Do you think reflection can be mostly implemented : using template?
Macro and reflection are different things. Macro is compiling time and reflection is runtime.
【在 s******n 的大作中提到】 : If there is such a macro system that's universally accepted : and all libs can reliably depend on it, it is effectively : a radical change to language itself. Achieving such a macro : system is no less difficult than having reflection built in.
No, not macro. C++ template is quite complicated and it's turing complete. Should be doable to implement something similar to reflection by using template.
【在 s******n 的大作中提到】 : If there is such a macro system that's universally accepted : and all libs can reliably depend on it, it is effectively : a radical change to language itself. Achieving such a macro : system is no less difficult than having reflection built in.
Some C++ people, when confronted with a problem, think “I know, I'll use template.”Now they have N+1 problems. Kidding aside, if you did it, you effectively created a new language. The question is whether other people speak the same language too.
【在 e****d 的大作中提到】 : No, not macro. C++ template is quite complicated and : it's turing complete. Should be doable to implement : something similar to reflection by using template.
Interesting ... how turing completeness at compile time is related to reflection at runtime?
【在 e****d 的大作中提到】 : No, not macro. C++ template is quite complicated and : it's turing complete. Should be doable to implement : something similar to reflection by using template.
【在 s******n 的大作中提到】 : Some C++ people, when confronted with a problem, think : “I know, I'll use template.”Now they have N+1 problems. : Kidding aside, if you did it, you effectively : created a new language. The question is whether : other people speak the same language too.
no, not complete yet. when you have no access to name of member/class/object , essentially you have no way to do reflection. the missing piece is the # name operator in preprocessor; if you don't have it, you have a big missing chain in the machine. so as you see, every "reflection simulator" library use macro here or there. i don't mean macro is reflection. but in current standard, the #name operator is almost the only way to implement reflection-like mechanism in a library. as for template, of course template is an important thing here, but it's not more important than other chains in the machine. the missing piece is always the most important, if you know what i mean (the shortest board decides the maximum capacity). that said, if the committee decides to add reflection, i am sure they have better way (e.g. better/complete RTTI support, as opposed to current vague "implementation-defined" RTTI)
【在 e****d 的大作中提到】 : No, not macro. C++ template is quite complicated and : it's turing complete. Should be doable to implement : something similar to reflection by using template.
Well, you cannot compare assembly with the others. Assembly is powerful, but not scalable. When I mentioned template is turing complete, I mean theoretically template can implement reflection. Some of them are quite straightforward such as checking whether a class has a member type, a member function or iterating its public data members. Of course, it will be difficult to implement a complete set of reflection functionalities.
【在 g*****g 的大作中提到】 : Interesting, assembly is also tuning complete, : and essentially it can do anything.
Life will be much easier if the language itself supports reflection. But before that, if we want to do something reflection-like in C++, template is the way to go. And definitely pre-processing will be used since it's a fundamental way to deal with tokens.
object missing a but piece
【在 t****t 的大作中提到】 : no, not complete yet. when you have no access to name of member/class/object : , essentially you have no way to do reflection. the missing piece is the # : name operator in preprocessor; if you don't have it, you have a big missing : chain in the machine. so as you see, every "reflection simulator" library : use macro here or there. : i don't mean macro is reflection. but in current standard, the #name : operator is almost the only way to implement reflection-like mechanism in a : library. as for template, of course template is an important thing here, but : it's not more important than other chains in the machine. the missing piece : is always the most important, if you know what i mean (the shortest board
anything is too cumbersome to use it is useless. you can use C++ to write JVM then by definition you have reflection! you can use function pointers and structs, who needs C++?
【在 e****d 的大作中提到】 : Well, you cannot compare assembly with the others. : Assembly is powerful, but not scalable. : When I mentioned template is turing complete, I mean : theoretically template can implement reflection. : Some of them are quite straightforward such as checking : whether a class has a member type, a member function or : iterating its public data members. Of course, it will be : difficult to implement a complete set of reflection : functionalities.
b*s
100 楼
在整个四川盆地下面埋上常温超导体,通过间歇改变超导磁性可以前进的,不用喷气……
可以外转内不转,这个不是技术难题 难题还是悬浮
【在 G*******h 的大作中提到】 : 可以外转内不转,这个不是技术难题 : 难题还是悬浮
W*y
101 楼
就说人脸识别吧,目前最先进的系统,仍然有人曾经举着一张照片挡住脸混过去。但是 美国安全局还是在往里面狠狠的砸钱。虽然每年没啥特别本质的进展,但并不妨碍给这 些人不停的送funding。因为这东西一旦做出来,对他们太有用了。 以上是Yi Ma 说的原话,大意。
You can ask Bjarne Stroustrup about who needs C++.
【在 D*******a 的大作中提到】 : anything is too cumbersome to use it is useless. : you can use C++ to write JVM then by definition you have reflection! : you can use function pointers and structs, who needs C++?
you totally missed the point. we use language constructs for convenience, to facilitate implementation. C has function pointers so it can be used to do what C++ can do (polymorphism, inheritance, etc). However, it is just very cumbersome and error prone. C++ has these functionalities built in so people can use them easily. As for reflection, you maybe smart enough to do it using template, but will that be as easy as Class.forName("...")? If programmer needs to jump through a lot of hoops, rewriting their old classes to do this, it is useless.
【在 e****d 的大作中提到】 : You can ask Bjarne Stroustrup about who needs C++.
The more I think about it, the more I feel that C++ template system is heading to the wrong direction. If they had transformed pre-processing into a real embedded language with APIs to compile-time objects, you can do all template can do with the same minimal run-time cost. And it will be much much easier to use and extend.
implementation. C (polymorphism, prone. C++ will through useless.
【在 D*******a 的大作中提到】 : you totally missed the point. : we use language constructs for convenience, to facilitate implementation. C : has function pointers so it can be used to do what C++ can do (polymorphism, : inheritance, etc). However, it is just very cumbersome and error prone. C++ : has these functionalities built in so people can use them easily. : As for reflection, you maybe smart enough to do it using template, but will : that be as easy as Class.forName("...")? If programmer needs to jump through : a lot of hoops, rewriting their old classes to do this, it is useless.
l*r
109 楼
地心电梯,快,省的bos远渡重洋了
【在 s*****o 的大作中提到】 : 在天上?不是个岛吗,要电梯干吗?
n*g
110 楼
同学们不要浮躁,有饭吃就行。管它有无前途,骗也是一门大学问,社会需要会忽悠的 人才。
e*d
111 楼
I think we are talking about different things. My point is you can still implement reflection-like logic using template + macro since c++ doesn't have built-in Reflection. Your point is that something is useless if it's cumbersome, which I don't disagree on.
C polymorphism, ++ will through
【在 D*******a 的大作中提到】 : you totally missed the point. : we use language constructs for convenience, to facilitate implementation. C : has function pointers so it can be used to do what C++ can do (polymorphism, : inheritance, etc). However, it is just very cumbersome and error prone. C++ : has these functionalities built in so people can use them easily. : As for reflection, you maybe smart enough to do it using template, but will : that be as easy as Class.forName("...")? If programmer needs to jump through : a lot of hoops, rewriting their old classes to do this, it is useless.
C++0x doesn't bring too much to template except variadic template and template alias. Preprocessing is about token scanning and processing, which is before the compilation stage. It might not be practical to put in any PP api in it.
【在 X****r 的大作中提到】 : The more I think about it, the more I feel that C++ template : system is heading to the wrong direction. : If they had transformed pre-processing into a real embedded : language with APIs to compile-time objects, you can do all : template can do with the same minimal run-time cost. And it : will be much much easier to use and extend. : : implementation. C : (polymorphism, : prone. C++
b*s
115 楼
其实那是个天梯……
在天上?不是个岛吗,要电梯干吗?
【在 s*****o 的大作中提到】 : 在天上?不是个岛吗,要电梯干吗?
k*g
116 楼
人臉是大泡沫。醫療是非勿擾。其餘的都是真的,就看有沒有找對下家。
t*t
117 楼
of course you can. i actually wrote a framework in my work so i am quite familiar with it. my colleagues use it and are happy with it, however they are not programmers. for me, an amateur programmer, the more i look at it i feel more stupid it is---macros are typeless and syntaxless, which is against the spirit of c++. it's not totally useless since our group use it everyday. but it is stupid. that's why i wish they have reflection in c++0x-- but no. of course it is built on template. but as i said, as a chain in the big picture, it's not more important than anything else -- for example, it's not more important than class, or string, or pointer-to-member. but macro is stupid.
【在 e****d 的大作中提到】 : I think we are talking about different things. My point is : you can still implement reflection-like logic using template + macro : since c++ doesn't have built-in Reflection. : Your point is that something is useless if it's cumbersome, which : I don't disagree on. : : C : polymorphism, : ++ : will
Yes, that's why I said transform. Well maybe I shouldn't have mentioned prerpocessing at all, because what I have imagined is totally different. e.g. instead of template class vector { ... }; template<> class vector { ... }; We could have (using % as a special symbol) %function vectorOf(%type T) { %var Name = "vectorOf" + T.name(); %if (T == %BuiltInTypes.boolean) { %return class $Name { ... }; } %else { %return class $Name { ... }; } } Not only this would make reflection-like compile-time constructs trivial, it also gives lot more freedoms. Say the two generated classes only differ in one line, we can make an %if on that line only. And no more SFINAE! Those might be good brain teasers, but there is really no point to use such convoluted way to retrieve what the compiler already knows. The error message would be much more sane, too.
【在 e****d 的大作中提到】 : C++0x doesn't bring too much to template except variadic : template and template alias. : Preprocessing is about token scanning and processing, which : is before the compilation stage. It might not be practical : to put in any PP api in it.
actually there is no need to make it so dramatic -- just make SFINAE everywhere (read: easy to use) and hidden. basically you need something like %if-%else (compile-time if) and compile conditionally according to that, while ignoring dead forks; and some additional operator/builtin function like typeof(), nameof() (class name, member name, etc), and a variant type ( something better than void*, such as boost::any) with proper exception.
【在 X****r 的大作中提到】 : Yes, that's why I said transform. Well maybe I shouldn't have : mentioned prerpocessing at all, because what I have imagined : is totally different. e.g. : instead of : template : class vector { : ... : }; : template<> : class vector {
Hmm, you are proposing generic compiler API and this is way too ambitious... boost type_traits is_same does the same. but it is based on temp specialization.
【在 X****r 的大作中提到】 : Yes, that's why I said transform. Well maybe I shouldn't have : mentioned prerpocessing at all, because what I have imagined : is totally different. e.g. : instead of : template : class vector { : ... : }; : template<> : class vector {
Except nameof(), there are equivalent items for the ones you suggested. Any obvious advantage to add them? %if-%else => template partial/explicit specialization + SFINAE typeof() => template partial/explicit specialization + auto + decltype + suffix function return syntax variant type => boost::any, template type parameter. It seems to me those items you suggested are cosmetic.
like (
【在 t****t 的大作中提到】 : actually there is no need to make it so dramatic -- just make SFINAE : everywhere (read: easy to use) and hidden. basically you need something like : %if-%else (compile-time if) and compile conditionally according to that, : while ignoring dead forks; and some additional operator/builtin function : like typeof(), nameof() (class name, member name, etc), and a variant type ( : something better than void*, such as boost::any) with proper exception.
It seems to be another compilation layer for metaprogramming.
【在 X****r 的大作中提到】 : Yes, that's why I said transform. Well maybe I shouldn't have : mentioned prerpocessing at all, because what I have imagined : is totally different. e.g. : instead of : template : class vector { : ... : }; : template<> : class vector {
i am referring to xentar's post. of course these are cosmetic, the whole template is cosmetic version of macro.
【在 e****d 的大作中提到】 : Except nameof(), there are equivalent items for the ones you : suggested. Any obvious advantage to add them? : %if-%else => template partial/explicit specialization + SFINAE : typeof() => template partial/explicit specialization + auto : + decltype + suffix function return syntax : variant type => boost::any, template type parameter. : It seems to me those items you suggested are cosmetic. : : like : (
is it not? basically a big macro with semantics. specialization is cosmetic version of #if. of course you get compiler support such as parameter check, and repetitive defintion don't get error, but essentially it's just macro.
【在 e****d 的大作中提到】 : It's interesting to know "the whole template is : cosmetic version of macro".
a*y
135 楼
I'm doing vision. Please tell me how to make a CVPR paper within less than 100 line Matlab.
My understanding of "cosmetic" change is that the change is minor. Will you give an example to find out whether a class has a public member function ro not by using macro instead of template?
cosmetic
【在 t****t 的大作中提到】 : is it not? basically a big macro with semantics. specialization is cosmetic : version of #if. : of course you get compiler support such as parameter check, and repetitive : defintion don't get error, but essentially it's just macro.
True。 ML和statistics还不能generalize到完全新的test data上(在某正程度上,你 可以叫他们test outliers。你给个全新的东西,其实即使是人,也不见得能认识)。 但如果你有大量的training data,ml and statistics make a lot sense,因为你非 常有可能在training data或他们的组合中找到相似或比较相似的东西,从而做出正确或合理的判 断。