I am working on a project that requires CGAL running on a mac and am very new to C++ in general. I installed CGAL using macports using the command sudo port install cgal The installation completed and the .h files were placed in /opt/local/include/cgal I copied the tutorial program into a .cpp file and compiled using g++ -lcgal -I/opt/local/include/ vec.cpp This returns the error ld
我正在开发一个需要在Mac上运行CGAL的项目，并且通常对C ++来说是非常新的。 我使用命令安装了CGAL sudo port install cgal 完成安装并将.h文件放入 /opt/local/include/cgal 我将教程程序复制到一个.cpp文件并使用编译 g++ -lcgal -I/opt/local/include/ vec.cpp 这会返回错误 ld：找不到-lcgal clang的库：error：linker命令失败，退出代码1（使用-v查看调用） g++ -lcgal -v -I/opt/local/include/ vec.cpp
Is the following legal in C and/or C++? void fn(); inline void fn() { /*Do something here*/ } What concerns me is that the first declaration looks like it implies that the function will be defined non-inline, but the following definition turns it into an inline after all. If there's a difference between C and C++ in this case, it would be nice to know that difference, too. Yes. In f
在C和/或C ++中以下是合法的吗？ void fn(); inline void fn() { /*Do something here*/ } 令我担心的是，第一个声明看起来像是暗示该函数将被定义为非内联函数，但下面的定义将其转化为内联函数。 如果在这种情况下C和C ++之间存在差异，那么也很高兴知道这种差异。 是。 实际上，这可能是最好的。 资料来源：http：//www.parashift.com/c++-faq/inline-nonmember-fns.html 经验法则：声明告诉你如何调用一个函数
this is my first post here... Is there any way to calculate a vector in the null space of another vector? I don't need the basis, just one vector in the null space will do. I already tried using the solve() method - colvec x(3); x = solve(A,B); where A is a 3x3 matrix of type mat - 2 2 2 3 3 3 4 4 4 and B is the zero vector of type colvec - 0 0 0 But the program terminates throwing
这是我第一次发帖... 有什么方法可以在另一个向量的空间中计算向量？ 我不需要这个基础，只有一个向量位于null空间中。 我已经尝试使用solve（）方法 - colvec x(3); x = solve(A,B); 其中A是mat的3x3矩阵 - 2 2 2 3 3 3 4 4 4 而B是colvec类型的零向量 - 0 0 0 但程序终止抛出以下错误 - error: solve(): solution not found terminate called after throwing an instance of 'std::runtime_error' what():
I have the following sample code: #include <iostream> #include <boost/program_options.hpp> int main ( int ac, char *av[] ) { // Declare the supported options. boost::program_options::options_description desc("Allowed options"); desc.add_options()("help", "produce help message"); boost::program_options::variables_map vm; boost::program_options::store(boost::progr
我有以下示例代码： #include <iostream> #include <boost/program_options.hpp> int main ( int ac, char *av[] ) { // Declare the supported options. boost::program_options::options_description desc("Allowed options"); desc.add_options()("help", "produce help message"); boost::program_options::variables_map vm; boost::program_options::store(boost::program_options::par
I'm using the following command to compile Boost 1.55 beta 1: b2 --toolset=msvc-12.0 architecture=x86 address-model=64 stage The result is a bunch of these errors: error C3861: 'assert_not_arg': identifier not found There is a list of supposed patches to make boost work with VS2013 here, but I have no idea how to use them. Apparently a similar problem is documented here, but
我正在使用以下命令来编译Boost 1.55 beta 1： b2 --toolset = msvc-12.0 architecture = x86 address-model = 64 stage 结果是一堆这些错误： 错误C3861：'assert_not_arg'：标识符未找到 这里有一个假设的补丁列表可以帮助VS2013进行提升，但我不知道如何使用它们。 显然这里记录了类似的问题，但我想知道是否有人成功构建了VS2013的Boost 64位（我不介意使用旧版本的boost，但他们似乎不支持MSVC 12.0编译器
This question already has an answer here: Case-insensitive string comparison in C++ [closed] 31 answers strncasecmp The strcasecmp() function performs a byte-by-byte comparison of the strings s1 and s2, ignoring the case of the characters. It returns an integer less than, equal to, or greater than zero if s1 is found, respectively, to be less than, to match, or be greater than s2. The st
这个问题在这里已经有了答案： C ++中不区分大小写的字符串比较[已关闭] 31个回答 strncasecmp strcasecmp()函数执行字符串s1和s2的逐字节比较，忽略字符的大小写。 如果找到s1，它将分别返回小于，等于或大于零的整数，使其小于，匹配或大于s2。 strncasecmp()函数是类似的，除了它比较不超过n个字节的s1和s2 ... 通常我所做的只是比较一个较低版本的字符串，例如： if (foo.make_this_lowercase_somehow() == "stac
From what I understand, the bitwise inclusive OR operator compares every bit in the first and second operand and returns 1 if either bit is 1. Bjarne Stroustrup uses it like this (ist being an istream object): ist.exceptions(ist.exceptions()|ios_base::bad_bit); I haven't really worked with bits a lot in programming, should it be on my to-do list to learn? I understand that if I had an int
根据我的理解，包含OR的运算符比较第一个和第二个操作数中的每一位，如果其中一个位为1，则返回1. Bjarne Stroustrup使用它（ist是istream对象）： ist.exceptions(ist.exceptions()|ios_base::bad_bit); 我在编程方面并没有真正使用过很多东西，它应该在我的待办事项列表上学习吗？ 我明白，如果我有一个int值为9，那么二进制文件就是00001001，但这非常重要。 我不明白他为什么会在他使用它的上下文中使用这个操作符。
I (stupidly) thought if I took the boolean result of true, cast to an int and left-shifted it I would end up with the LSB repeated at every bit, obviously not! If I had a boolean result and I wanted to convert this to all ones for true and all zeros for false, what would be the cheapest way (computationally) to do this? bool result = x == y; unsigned int x = 0; //x becomes all ones when resu
我（愚蠢地）认为如果我将true的布尔结果转换为int并将其左移，那么我将最终在每一位都重复LSB，显然不是！ 如果我有一个布尔结果，并且我想将其转换为全部为真或全为零，那么最简单的方法是（计算）如何执行此操作？ bool result = x == y; unsigned int x = 0; //x becomes all ones when result is true //x becomes all zeros when result is false 像这样，也许： bool result = x == y; unsigned int z = -result; 更
what's the best way to perform bitwise operations on vector<bool> ? as i understand, vector<bool> is a specialisation that uses one bit per boolean. I chose vector<bool> for memory saving reasons. I know that there are some problems with vector<bool> but for my needs it's apropriate. now - what's the most performant way of aplying bitwise operations to wh
在vector<bool>上执行按位运算的最佳方法是什么？ 据我了解， vector<bool>是一种专门化，每布尔值使用一个位。 为了节省内存的原因，我选择了vector<bool> 。 我知道vector<bool>存在一些问题，但为了我的需要，它是合适的。 现在 - 对整个这种向量应用按位运算的最高性能方式是什么？ 如果我在for循环中读取并读出每个单独的bool并将其存储回来，那么我会了解更多操作，以便访问实际值。 谢
Is there any reason not to use the bitwise operators &, |, and ^ for "bool" values in C++? I sometimes run into situations where I want exactly one of two conditions to be true (XOR), so I just throw the ^ operator into a conditional expression. I also sometimes want all parts of a condition to be evaluated whether the result is true or not (rather than short-circuiting), so I us
是否有任何理由不在C ++中使用按位运算符＆，|和^作为“bool”值？ 有时我会遇到两种条件中的一种必须为真（XOR）的情况，所以我只是将^运算符放入条件表达式中。 我有时也希望评估一个条件的所有部分，不管结果是否正确（而不是短路），所以我使用＆和|。 我也需要累积布尔值，而且＆=和| =可能非常有用。 在做这件事情时，我收到了一些提出的眉毛，但代码仍然比其他方式更有意义和更清晰。 有没有任何理由不使用这些bools