This question already has an answer here: What is an undefined reference/unresolved external symbol error and how do I fix it? 27 answers Actually, an edit to the question would be nice, but, I think I have an idea bout what going on : It looks like you are trying to separately compile a function template. This meaning that you are doing the following : g++ ScenarioResult.cpp -lboost_seri
这个问题在这里已经有了答案： 什么是未定义的引用/未解析的外部符号错误，我该如何解决它？ 27个答案 其实，对这个问题的编辑会很好，但是，我认为我有一个想法来回答这个问题：看起来你正试图单独编译一个函数模板。 这意味着您正在执行以下操作： g++ ScenarioResult.cpp -lboost_serialization 这是抛出错误。 ScenarioResult :: serialize是a template function ，这意味着它根据传递给的模板参数的类型被实例化
Does the boost serialization library support serialization of std::unique_ptr? I tried to compile the code below, but if I include the boost::archive::text_oarchive oa(ofs); oa << g; line, the compiler (btw gcc4.7 with -std=c++11 flag) throws an error /usr/include/boost/serialization/access.hpp:118:9: error: 'class std::unique_ptr' has no member named 'serialize' #in
boost序列化库是否支持std :: unique_ptr的序列化？ 我试图编译下面的代码，但是如果我包含boost :: archive :: text_oarchive oa（ofs）; oa << g; 线， 编译器（带有-std = c ++ 11标志的bcc gcc4.7）会抛出一个错误 /usr/include/boost/serialization/access.hpp:118:9：error：'class std :: unique_ptr'has no member named'serialize' #include <iostream> #include <memory> #i
I am using boost serialization. I compiled with: -L/opt/local/lib -lboost_serialization -stdlib=libc++ , but got several (ungooglable) errors: Undefined symbols for architecture x86_64: "boost::archive::text_oarchive_impl::save(std::__1::basic_string, std::__1::allocator > const&)", referenced from: void boost::archive::save_access::save_primitive, std::__1::allocator > >(boost::archiv
我正在使用boost序列化。 我编译了： -L/opt/local/lib -lboost_serialization -stdlib=libc++ ，但得到了几个（不可更改的）错误： Undefined symbols for architecture x86_64: "boost::archive::text_oarchive_impl::save(std::__1::basic_string, std::__1::allocator > const&)", referenced from: void boost::archive::save_access::save_primitive, std::__1::allocator > >(boost::archive::text_oarchive&,
Possible Duplicate: cout << order of call to functions it prints? Undefined Behavior and Sequence Points Why does this code print 2 1 0? #include <iostream> struct A{ int p; A():p(0){} int get(){ return p++; } }; int main(){ A a; std::cout<<a.get()<<" "<<a.get()<<" "<<a.get()<<std::endl; } As I stated in my comment, there'
可能重复： cout <<打印函数的调用顺序？ 未定义的行为和序列点 为什么此代码打印2 1 0？ #include <iostream> struct A{ int p; A():p(0){} int get(){ return p++; } }; int main(){ A a; std::cout<<a.get()<<" "<<a.get()<<" "<<a.get()<<std::endl; } 正如我在我的评论中所说的，没有序列点...... 根据Stroustrup的The C ++ Programming Langua
Why does the C++ STL not provide any "tree" containers, and what's the best thing to use instead? I want to store a hierarchy of objects as a tree, rather than use a tree as a performance enhancement... There are two reasons you could want to use a tree: You want to mirror the problem using a tree-like structure: For this we have boost graph library Or you want a container
为什么C ++ STL不提供任何“树”容器，而最好使用什么呢？ 我想将对象的层次结构存储为树，而不是将树用作性能增强... 有两个理由可以使用树： 你想用树形结构来反映问题： 为此，我们增强了图形库 或者你想要一个像访问特性这样的树的容器 std::map std::set 基本上这两个容器的特点是它们实际上必须使用树来实现（尽管这实际上并不是要求）。 另请参阅此问题：C树实现 可能出于同样的原因，没有增加树形容器
Can we create the following array or something similar using template in c++ at compile time. int powerOf2[] = {1,2,4,8,16,32,64,128,256} This is the closest I got. template <int Y> struct PowerArray{enum { value=2* PowerArray<Y-1>::value };}; but then to use I need something like PowerArray <i> which compiler gives error as i is dynamic variable. You can use BOOST_PP_
我们可以在编译时使用c ++中的模板创建下面的数组或类似的东西。 int powerOf2 [] = {1,2,4,8,16,32,64,128,256} 这是我得到的最接近的。 template <int Y> struct PowerArray{enum { value=2* PowerArray<Y-1>::value };}; 但随后使用我需要像PowerArray <i>这样的编译器给出的错误，因为我是动态变量。 你可以使用BOOST_PP_ENUM来达到这个目的： #include <iostream> #include <cmath>
One can define a static array at compile time as follows: const std::size_t size = 5; unsigned int list[size] = { 1, 2, 3, 4, 5 }; Question 1 - Is it possible by using various kinds of metaprogramming techniques to assign these values "programmatically" at compile time? Question 2 - Assuming all the values in the array are to be the same barr a few, is it possible to selectively
可以在编译时定义一个静态数组，如下所示： const std::size_t size = 5; unsigned int list[size] = { 1, 2, 3, 4, 5 }; 问题1 - 是否可以通过使用各种元编程技术在编译时“编程”分配这些值？ 问题2 - 假设数组中的所有值都是相同的barr，是否可以在编译时以编程方式有选择地分配值？ 例如： const std::size_t size = 7; unsigned int list[size] = { 0, 0, 2, 3, 0, 0, 0 }; 欢迎使用C ++ 0x的解决方案
I would like to see how this example of existing code would be able to take advantage of the C++0x initializer list feature. Example0: #include <vector> #include <string> struct Ask { std::string prompt; Ask(std::string a_prompt):prompt(a_prompt){} }; struct AskString : public Ask{ int min; int max; AskString(std::string a_prompt, int a_min, int a_max):
我想看看现有代码的这个例子如何能够利用C ++ 0x初始值设定项列表功能。 Example0： #include <vector> #include <string> struct Ask { std::string prompt; Ask(std::string a_prompt):prompt(a_prompt){} }; struct AskString : public Ask{ int min; int max; AskString(std::string a_prompt, int a_min, int a_max): Ask(a_prompt), min(a_min), max(a_max){} }; int main() {
Here is the problem: In the main thread (io - boost::asio::io_service): io.post(functor1, callback1) .... io.post(functorN, callbackN) io.join() <--- waiting while all the task to be processed and continue to execute the program The code is executed in a loop. boost::thread_group would perfectly match, but it creates new threads all the times, while I want to create working threads only
这是问题： 在主线程（io - boost :: asio :: io_service）中： io.post(functor1, callback1) .... io.post(functorN, callbackN) io.join() <--- waiting while all the task to be processed and continue to execute the program 代码在循环中执行。 boost::thread_group可以完美匹配，但它boost::thread_group创建新线程，而我只想创建工作线程一次， boost::thread_group派遣任务。 我所见过的所有线程线程都
When using boost::asio for some asynchronous TCP communication I noticed it starts a lot of (3-4) internal threads. Reading in the documentation, it says "The implementation of this library for a particular platform may make use of one or more internal threads to emulate asynchronicity" Now my lib has very strict requirements to not start any extra threads (except one that is supplied by the
当使用boost :: asio进行一些异步TCP通信时，我注意到它启动了很多（3-4）内部线程。 它说，阅读文档 "The implementation of this library for a particular platform may make use of one or more internal threads to emulate asynchronicity" 现在我的lib有非常严格的要求，不会启动任何额外的线程（除了由客户端提供的并且现在启动io_service::run() ）的线程外。 有没有什么办法可以停止boost :: asio来创建这些额外