矢量

Question

我想使用boost ::變種

std::vector<boost::variant<mesh::Entity&, mesh::Vertex, mesh::Edge> > 
    xField::getZeros(const mesh::Region& s, char *EntityS) const 
{ 
//Vertex 
    if(EntityS == "V") 
    { 
    std::vector<mesh::Vertex> zeros; 
    for(Region::vertexIterator itv = s.beginVertex(); 
     itv != s.endVertex(); ++itv) 
    { 
     if(abs(getVal(*itv)) < 1.e-12)  
     zeros.push_back(*itv); 
    } 
     return zeros;  
    } 
else if .. 

，但我收到的錯誤： 錯誤：轉換，從「的std :: vector」的非標型「的std ::矢量>」請求

編輯：

zeroVector xField::getZeros(const mesh::Region& s, char *EntityS) const 
{ 
//Vertex 
    if(EntityS == "V") 
    { 
    zeroVector zeros; 
    for(Region::vertexIterator itv = s.beginVertex(); itv != s.endVertex(); ++itv) 
    { 
     if(abs(getVal(*itv)) < 1.e-12)  
     zeros.push_back(zeroVariant(*itv)); 
    } 
     return zeros; 

和我在h文件的typedef定義

typedef boost::variant<mesh::Entity&, mesh::Vertex, mesh::Edge> zeroVariant; 
typedef std::vector<zeroVariant> zeroVector; 

，現在我已經得到了以下錯誤：

/softs/boost/1.53.0/64/gcc/4.5.1/include/boost/detail/reference_content.hpp：在成員函數「 void boost :: detail :: variant :: assign_storage :: internal_visit（T &，int）const [with T = boost :: detail :: reference_content]'： /softs/boost/1.53.0/64/gcc/4.5 .1/include/boost/variant/detail/visiting_impl.hpp：130：9：從'typename Visitor :: result_type boost :: detail :: variant :: visitation_impl_invoke_impl'實例化（int，Visitor &，VoidPtrCV，T *，mpl_： ：true_）[with Visitor = boost :: detail :: variant :: assign_storage，VoidPtrCV = void *，T = boost :: detail :: reference_content，typename Visitor :: re sult_type = void，mpl _ :: true_ = mpl _ :: bool_]' /softs/boost/1.53.0/64/gcc/4.5.1/include/boost/variant/detail/visitation_impl.hpp:173:9：實例化from'typename Visitor :: result_type boost :: detail :: variant :: visitation_impl_invoke（int，Visitor &，VoidPtrCV，T *，NoBackupFlag，int）[with Visitor = boost :: detail :: variant :: assign_storage，VoidPtrCV = void *，T = boost :: detail :: reference_content，NoBackupFlag = boost :: variant :: has_fallback_type_，typename Visitor :: result_type = void]' /softs/boost/1.53.0/64/gcc/4.5.1/include /boost/variant/detail/visitation_impl.hpp:260:1：實例化來自'typename Visitor :: result_type boost :: detail :: variant :: visitation_impl（int，int，Visitor &，VoidPtrCV，mpl _ :: false_，NoBackupFlag，其中*，step0 *）[其中= mpl _ :: int_ < 0>，step0 = boost :: detail :: variant :: visitation_impl_step，boost :: detail :: re ference_content，boost :: mpl :: l_item，mesh :: Vertex，boost :: mpl :: l_item，mesh :: Edge，boost :: mpl :: l_end >> boost :: mpl :: l_iter >>，Visitor = boost :: detail :: variant :: assign_storage，VoidPtrCV = void *，NoBackupFlag = boost :: variant :: has_fallback_type_，typename Visitor :: result_type = void，mpl _ :: false_ = mpl _ :: bool_]' /softs/boost/1.53.0/64/gcc/4.5.1/include/boost/variant/variant.hpp：2326：13：從靜態類型實例化Visitor :: result_type boost :: variant :: internal_apply_visitor_impl（int，int，Visitor &，VoidPtrCV）[with Visitor = boost :: detail :: variant :: assign_storage，VoidPtrCV = void *，T0_ = mesh :: Entity &，T1 = mesh :: Vertex，T2 = mesh :: Edge，T3 = boost： ：detail :: variant :: void_，T4 = boost :: detail :: variant :: void_，T5 = boost :: detail :: variant :: void_，T6 = boost :: detail :: variant :: void_，T7 = boost :: detail :: variant :: void_，T8 = boost :: detail :: variant :: void_，T9 = boost :: detail :: varia nt :: void_，T10 = boost :: detail :: variant :: void_，T11 = boost :: detail :: variant :: void_，T12 = boost :: detail :: variant :: void_，T13 = boost :: detail :: variant :: void_，T14 = boost :: detail :: variant :: void_，T15 = boost :: detail :: variant :: void_，T16 = boost :: detail :: variant :: void_，T17 = boost： ：detail :: variant :: void_，T18 = boost :: detail :: variant :: void_，T19 = boost :: detail :: variant :: void_，typename Visitor :: result_type = void]' /softs/boost/1.53.0/64/GCC/4.5.1 /包括/升壓/變體/變體。hpp：2337：13：實例化來自'typename Visitor :: result_type boost :: variant :: internal_apply_visitor（Visitor &）[with Visitor = boost :: detail :: variant :: assign_storage，T0_ = mesh :: Entity &，T1 = mesh :: Vertex，T2 = mesh :: Edge，T3 = boost :: detail :: variant :: void_，T4 = boost :: detail :: variant :: void_，T5 = boost :: detail :: variant :: void_ ，T6 = boost :: detail :: variant :: void_，T7 = boost :: detail :: variant :: void_，T8 = boost :: detail :: variant :: void_，T9 = boost :: detail :: variant： ：void_，T10 = boost :: detail :: variant :: void_，T11 = boost :: detail :: variant :: void_，T12 = boost :: detail :: variant :: void_，T13 = boost :: detail :: variant :: void_，T14 = boost :: detail :: variant :: void_，T15 = boost :: detail :: variant :: void_，T16 = boost :: detail :: variant :: void_，T17 = boost :: detail :: variant :: void_，T18 = boost :: detail :: variant :: void_，T19 = boost :: detail :: variant :: void_，typename Visitor :: result_type = void]' /softs/boost /從'void boost :: variant :: variant_assign'（const boost :: variant &）[使用T0_ = mesh的實例化版本：1.53.0/64/gcc/4.5.1/include/boost/variant /variant.hpp:2085:13 :: Entity &，T1 = mesh :: Vertex，T2 = mesh :: Edge，T3 = boost :: detail :: variant :: void_，T4 = boost :: detail :: variant :: void_，T5 = boost :: detail：variant :: void_，T6 = boost :: detail :: variant :: void_，T7 = boost :: detail :: variant :: void_，T8 = boost :: detail :: variant :: void_，T9 = boost :: detail :: variant :: void_，T10 = boost :: detail :: variant :: void_，T11 = boost :: detail :: variant :: void_，T12 = boost :: detail :: variant :: void_，T13 = boost :: detail :: variant :: void_，T14 = boost :: detail :: variant :: void_，T15 = boost :: detail :: variant :: void_，T16 = boost :: detail :: variant :: void_ ，T17 = boost :: detail :: variant :: void_，T18 = boost :: detail :: variant :: void_，T19 = boost :: detail :: variant :: void_，boost :: variant = boost :: variant] ' /softs/boost/1.53.0/64/gcc/4.5.1/inclu實例化來自'boost :: variant & boost :: variant :: operator =（const boost :: variant &）[with T0_ = mesh :: Entity &，T1 = mesh :: Vertex，T2 = mesh :: Edge，T3 = boost :: detail :: variant :: void_，T4 = boost :: detail :: variant :: void_，T5 = boost :: detail :: variant :: void_ ，T6 = boost :: detail :: variant :: void_，T7 = boost :: detail :: variant :: void_，T8 = boost :: detail :: variant :: void_，T9 = boost :: detail :: variant： ：void_，T10 = boost :: detail :: variant :: void_，T11 = boost :: detail :: variant :: void_，T12 = boost :: detail :: variant :: void_，T13 = boost :: detail :: variant :: void_，T14 = boost :: detail :: variant :: void_，T15 = boost :: detail :: variant :: void_，T16 = boost :: detail :: variant :: void_，T17 = boost :: detail :: variant :: void_，T18 = boost :: detail :: variant :: void_，T19 = boost :: detail :: variant :: void_，boost :: variant = boost :: variant]' /usr/include/C++/4.5 /比特/ vector.tcc：312：4：從'void std :: vector < _Tp，_Alloc :: :: M_insert_aux（std :: vector < _Tp，_Alloc> :: iterator，const _Tp &）實例化[with _Tp = boost :: variant ，_Alloc = std :: allocator>，std :: vector < _Tp，_Alloc> :: iterator = __gnu_cxx :: __ normal_iterator *，std :: vector >>，typename std :: _ Vector_base < _Tp，_Alloc> :: _ Tp_alloc_type :: 'void std :: vector < _Tp，_Alloc> :: push_back（const value_type &） [with _Tp = boost :: variant，_Alloc = std :: allocator>，value_type = boost :: variant]' /home/mycode.cc:128:42：從這裏實例化 /softs/boost/1.53.0/ 64/gcc/4.5.1/include/boost/detail/reference_content.hpp：62：24：錯誤：'boost :: detail :: reference_content & boost :: detail :: reference_content :: operator =（const boost :: detail :: reference_content &）[with RefT = mesh :: Entity &，boost :: detail :: reference_content = boost :: detail :: reference_content]'是私人的 /softs/boost/1.53.0/64/gcc/4.5.1/include/boost/variant/variant.hpp:526:9：錯誤：在此範圍內

在此先感謝!!!!!

Answer 1

您需要更改'零'類型 - 它不能從std::vector<mesh::Vertex>轉換爲您的變體類型的向量。使用一些類型定義，以使代碼更簡潔一些太：

typedef boost::variant<mesh::Entity&, mesh::Vertex, mesh::Edge> EvVariant; 
typedef std::vector<EvVariant> EvVariantVector; 

EvVariantVector xField::getZeros(const mesh::Region& s, char *EntityS) const 
{ 
//Vertex 
    if(EntityS == "V") // This line is probably a bug! 
    { 
    EvVariantVector zeros; // Use the return type here! 
    for(Region::vertexIterator itv = s.beginVertex(); itv != s.endVertex(); ++itv) 
    { 
     if(abs(getVal(*itv)) < 1.e-12)  
     zeros.push_back(EvVariant(*itv)); 
    } 
     return zeros;  
    } 
else if .. 

還行if (EntityS == "V")是不正確的，並很可能會失敗。使用strcmp或只比較字符串的第一個字符。