SOA/interface/TableExaminer.h

0001 #ifndef FWCore_SOA_TableExaminer_h
0002 #define FWCore_SOA_TableExaminer_h
0003 // -*- C++ -*-
0004 //
0005 // Package:     FWCore/SOA
0006 // Class  :     TableExaminer
0007 //
0008 /**\class TableExaminer TableExaminer.h "TableExaminer.h"
0009
0010  Description: Concrete implementation of TableExaminerBase
0011
0012  Usage:
0013     <usage>
0014
0015 */
0016 //
0017 // Original Author:  Chris Jones
0018 //         Created:  Mon, 28 Aug 2017 14:22:29 GMT
0019 //
0020
0021 // system include files
0022
0023 // user include files
0024 #include "FWCore/SOA/interface/TableExaminerBase.h"
0025
0026 // forward declarations
0027 namespace edm {
0028   namespace soa {
0029
0030     template <typename T>
0031     class TableExaminer : public TableExaminerBase {
0032     public:
0033       explicit TableExaminer(T const* iTable) : m_table(iTable) {}
0034
0035       TableExaminer(const TableExaminer<T>&) = default;
0036
0037       TableExaminer<T>& operator=(const TableExaminer<T>&) = default;
0038
0039       ~TableExaminer() override {}
0040
0041       // ---------- const member functions ---------------------
0042
0043       size_t size() const final { return m_table->size(); }
0044
0045       void const* columnAddress(unsigned int iColumnIndex) const final {
0046         return m_table->columnAddressByIndex(iColumnIndex);
0047       }
0048
0049       std::vector<std::type_index> columnTypes() const final {
0050         std::vector<std::type_index> returnValue;
0051         returnValue.reserve(T::kNColumns);
0052         columnTypesImpl<0, T::kNColumns>(returnValue);
0053         return returnValue;
0054       }
0055
0056       std::vector<std::pair<char const*, std::type_index>> columnDescriptions() const final {
0057         std::vector<std::pair<char const*, std::type_index>> returnValue;
0058         returnValue.reserve(T::kNColumns);
0059         columnDescImpl<0, T::kNColumns>(returnValue);
0060         return returnValue;
0061       }
0062
0063       const std::type_info* typeID() const final { return &typeid(T); }
0064
0065     private:
0066       template <int I, int S>
0067       void columnTypesImpl(std::vector<std::type_index>& iV) const {
0068         if constexpr (I != S) {
0069           using Layout = typename T::Layout;
0070           iV.emplace_back(typeid(typename std::tuple_element<I, Layout>::type));
0071           columnTypesImpl<I + 1, S>(iV);
0072         }
0073       }
0074
0075       template <int I, int S>
0076       void columnDescImpl(std::vector<std::pair<char const*, std::type_index>>& iV) const {
0077         if constexpr (I != S) {
0078           using Layout = typename T::Layout;
0079           using ColumnType = typename std::tuple_element<I, Layout>::type;
0080           iV.emplace_back(ColumnType::label(), typeid(typename ColumnType::type));
0081           columnDescImpl<I + 1, S>(iV);
0082         }
0083       }
0084
0085       // ---------- member data --------------------------------
0086       T const* m_table;
0087     };
0088
0089   }  // namespace soa
0090 }  // namespace edm
0091
0092 #endif