struct arch32 {};
struct arch64 {};

namespace PE {
namespace Section {
    class Detail
    {
    public:
        template<typename Arch>
        Detail(const ImgSectionHeader& header, const Image<Arch>& image);
        double   entropy() const;

template  Detail::Detail(const ImgSectionHeader& header, const Image<arch32>& image);
template  Detail::Detail(const ImgSectionHeader& header, const Image<arch64>& image);

implementation.obj : error LNK2019: unresolved external symbol "public: double __thiscall PE::Section::Detail::entropy(void)const " (?entropy@Detail@Section@PE@@QBENXZ) referenced in function "private: void __thiscall readpe::OutputFormatter<struct PE::arch32>::formatSectionsDetails(void)" (?formatSectionsDetails@?$OutputFormatter@Uarch32@PE@@@readpe@@AAEXXZ)

template  Detail::Detail<arch32>(const ImgSectionHeader& header, const Image<arch32>& image);
template  Detail::Detail<arch64>(const ImgSectionHeader& header, const Image<arch64>& image);

c:projectscpp-workspacereadpesrcpeimplementationsectionsection.hpp(114): error C2143: syntax error : missing ';' before '<'
c:projectscpp-workspacereadpesrcpeimplementationsectionsection.hpp(114): error C2059: syntax error : '<'
c:projectscpp-workspacereadpesrcpeimplementationsectionsection.hpp(115): error C2143: syntax error : missing ';' before '<'
c:projectscpp-workspacereadpesrcpeimplementationsectionsection.hpp(115): error C2059: syntax error : '<'

template  Detail::Detail(const ImgSectionHeader& header, const Image<arch32>& image);
template  Detail::Detail(const ImgSectionHeader& header, const Image<arch64>& image);