我在VS2015中创建了一个新的C ++（空）项目，然后将Eigen 3.3.1源代码放在一个＆＃39; inc＆＃39;解决方案目录中的文件夹，例如，Matrix.h的路径是 inc / Eigen / Core / 。我已将此 inc / 路径设置为附加的包含目录，并且还尝试使用 inc / Eigen / 作为另一个包含目录，以防文件出现问题，包括彼此，但这没有改变。
在main.cpp中，我有以下内容：
#include "Eigen/Core/Matrix.h"
int main()
{
return 0;
}
在编译x64时，这给了我：
1>c:\users\brody\documents\visual studio 2015\projects\eigentest\inc\eigen\core\matrix.h(18): error C2988: unrecognizable template declaration/definition
1>c:\users\brody\documents\visual studio 2015\projects\eigentest\inc\eigen\core\matrix.h(18): error C2143: syntax error: missing ';' before '<'
1>c:\users\brody\documents\visual studio 2015\projects\eigentest\inc\eigen\core\matrix.h(18): error C2059: syntax error: '<'
1>c:\users\brody\documents\visual studio 2015\projects\eigentest\inc\eigen\core\matrix.h(19): error C2143: syntax error: missing ';' before '{'
1>c:\users\brody\documents\visual studio 2015\projects\eigentest\inc\eigen\core\matrix.h(19): error C2447: '{': missing function header (old-style formal list?)
1>c:\users\brody\documents\visual studio 2015\projects\eigentest\inc\eigen\core\matrix.h(179): error C2143: syntax error: missing ',' before '<'
1> c:\users\brody\documents\visual studio 2015\projects\eigentest\inc\eigen\core\matrix.h(404): note: see reference to class template instantiation 'Eigen::Matrix<_Scalar,_Rows,_Cols,_Options,_MaxRows,_MaxCols>' being compiled
1>c:\users\brody\documents\visual studio 2015\projects\eigentest\inc\eigen\core\matrix.h(186): error C2143: syntax error: missing ';' before '<'
1>c:\users\brody\documents\visual studio 2015\projects\eigentest\inc\eigen\core\matrix.h(186): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>c:\users\brody\documents\visual studio 2015\projects\eigentest\inc\eigen\core\matrix.h(186): error C2238: unexpected token(s) preceding ';'
1>c:\users\brody\documents\visual studio 2015\projects\eigentest\inc\eigen\core\matrix.h(192): error C2653: 'Base': is not a class or namespace name
1>c:\users\brody\documents\visual studio 2015\projects\eigentest\inc\eigen\core\matrix.h(192): error C2144: syntax error: 'int' should be preceded by ';'
1>c:\users\brody\documents\visual studio 2015\projects\eigentest\inc\eigen\core\matrix.h(192): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>c:\users\brody\documents\visual studio 2015\projects\eigentest\inc\eigen\core\matrix.h(192): warning C4183: 'EIGEN_DENSE_PUBLIC_INTERFACE': missing return type; assumed to be a member function returning 'int'
1>c:\users\brody\documents\visual studio 2015\projects\eigentest\inc\eigen\core\matrix.h(192): error C3646: 'PlainObject': unknown override specifier
1>c:\users\brody\documents\visual studio 2015\projects\eigentest\inc\eigen\core\matrix.h(194): error C2653: 'Base': is not a class or namespace name
1>c:\users\brody\documents\visual studio 2015\projects\eigentest\inc\eigen\core\matrix.h(195): error C2653: 'Base': is not a class or namespace name
1>c:\users\brody\documents\visual studio 2015\projects\eigentest\inc\eigen\core\matrix.h(206): error C3646: 'EIGEN_STRONG_INLINE': unknown override specifier
1>c:\users\brody\documents\visual studio 2015\projects\eigentest\inc\eigen\core\matrix.h(206): error C3646: 'Matrix': unknown override specifier
1>c:\users\brody\documents\visual studio 2015\projects\eigentest\inc\eigen\core\matrix.h(206): error C2143: syntax error: missing ';' before '&'
1>c:\users\brody\documents\visual studio 2015\projects\eigentest\inc\eigen\core\matrix.h(206): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>c:\users\brody\documents\visual studio 2015\projects\eigentest\inc\eigen\core\matrix.h(207): error C2334: unexpected token(s) preceding '{'; skipping apparent function body
1>c:\users\brody\documents\visual studio 2015\projects\eigentest\inc\eigen\core\matrix.h(223): error C2061: syntax error: identifier 'EIGEN_STRONG_INLINE'
1>c:\users\brody\documents\visual studio 2015\projects\eigentest\inc\eigen\core\matrix.h(237): error C2334: unexpected token(s) preceding '{'; skipping apparent function body
1>c:\users\brody\documents\visual studio 2015\projects\eigentest\inc\eigen\core\matrix.h(243): error C2061: syntax error: identifier 'EIGEN_STRONG_INLINE'
1>c:\users\brody\documents\visual studio 2015\projects\eigentest\inc\eigen\core\matrix.h(259): error C2334: unexpected token(s) preceding ':'; skipping apparent function body
1>c:\users\brody\documents\visual studio 2015\projects\eigentest\inc\eigen\core\matrix.h(14): fatal error C1075: the left brace '{' was unmatched at the end of the file
抱怨Matrix.h第18行：
#ifndef EIGEN_MATRIX_H
#define EIGEN_MATRIX_H
namespace Eigen {
namespace internal {
template<typename _Scalar, int _Rows, int _Cols, int _Options, int _MaxRows, int _MaxCols>
struct traits<Matrix<_Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols> > // line 18
{
private:
// etc...
任何其他Eigen #include都会出现类似的问题。我是否错过了一些必需的#include订单或一些编译标志或设置？谢谢！
答案 0 :(得分：0)
您必须复制整个Eigen目录，而不仅仅是src子文件夹。并且您不能直接包含src子文件夹中的文件，而是将文件包含在Eigen目录中。例如，#include <Eigen/Core>将包括所有核心功能，#include <Eigen/Dense>将包括所有密集功能（包括核心，几何和分解）。