.. _program_listing_file_src_rdf4cpp_query_QuadPattern.cpp:

Program Listing for File QuadPattern.cpp
========================================

|exhale_lsh| :ref:`Return to documentation for file <file_src_rdf4cpp_query_QuadPattern.cpp>` (``src/rdf4cpp/query/QuadPattern.cpp``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   #include "QuadPattern.hpp"
   
   #include <rdf4cpp/writer/WriteQuad.hpp>
   
   namespace rdf4cpp::query {
   
   QuadPattern::QuadPattern(Node graph, Node subject, Node predicate, Node object) noexcept : entries_{graph, subject, predicate, object} {
   }
   
   bool QuadPattern::valid() const noexcept {
       return (graph().is_iri() || graph().is_variable())
               && !subject().is_literal()
               && (predicate().is_iri() || predicate().is_variable())
               && !object().null();
   }
   
   QuadPattern::operator std::string() const {
       auto s = writer::StringWriter::oneshot([this](auto &w) {
           return writer::write_quad<writer::OutputFormat::NQuads>(*this, w, nullptr);
       });
   
       s.pop_back(); // remove newline
       return s;
   }
   
   std::ostream &operator<<(std::ostream &os, const QuadPattern &pattern) {
       os << static_cast<std::string>(pattern);
       return os;
   }
   
   QuadPattern QuadPattern::to_node_storage(storage::DynNodeStoragePtr node_storage) const {
       QuadPattern qp;
       auto it = qp.begin();
       for (const auto &item : *this) {
           *(it++) = item.to_node_storage(node_storage);
       }
       return qp;
   }
   
   QuadPattern QuadPattern::try_get_in_node_storage(storage::DynNodeStoragePtr node_storage) const noexcept {
       QuadPattern qp;
       auto it = qp.begin();
       for (const auto &item : *this) {
           *(it++) = item.try_get_in_node_storage(node_storage);
       }
       return qp;
   }
   
   TriplePattern const &QuadPattern::without_graph() const noexcept {
       static_assert(sizeof(QuadPattern) == 4 * sizeof(Node));
       static_assert(sizeof(TriplePattern) == 3 * sizeof(Node));
       return *reinterpret_cast<TriplePattern const *>(entries_.data() + 1);
   }
   
   }  // namespace rdf4cpp::query