added conversion from/to blob

include/matador/sql/convert.hpp

@@ -55,6 +55,12 @@ void convert(std::string &dest, SourceType source, typename std::enable_if<std::
   }
 }
 
+template < typename SourceType >
+void convert(utils::blob &dest, SourceType source, typename std::enable_if<!std::is_same<utils::blob, SourceType>::value>::type* = nullptr)
+{
+  throw std::logic_error("couldn't convert value to matador::utils::blob");
+}
+
 void convert(std::string &dest, const char* source);
 
 unsigned long long to_unsigned_long_long(const char *source);
@@ -108,8 +114,11 @@ void convert(DestType &dest, bool source, typename std::enable_if<std::is_floati
 template < typename DestType >
 void convert(DestType &dest, const utils::blob &data)
 {
+  throw std::logic_error("couldn't convert matador::utils::blob into destination type");
 }
 
+void convert(utils::blob &dest, const utils::blob &data);
+
 }
 
 #endif //QUERY_CONVERT_HPP

src/sql/convert.cpp

@@ -59,4 +59,9 @@ long double to_double(const char *source)
   return result;
 }
 
+void convert(utils::blob &dest, const utils::blob &data)
+{
+  dest = data;
+}
+
 }

test/FieldTest.cpp

@@ -2,10 +2,10 @@
 
 #include "matador/sql/field.hpp"
 
-using namespace matador::sql;
+using namespace matador;
 
 TEST_CASE("Field test", "[field]") {
-  field f("name");
+  sql::field f("name");
 
   REQUIRE(f.name() == "name");
   REQUIRE(f.is_null());
@@ -35,4 +35,18 @@ TEST_CASE("Field test", "[field]") {
   auto bool_val = f.as<bool>();
   REQUIRE(bool_val.has_value());
   REQUIRE(bool_val.value());
+
+  f = utils::blob{ 7,8,6,5,4,3 };
+  REQUIRE(!f.is_null());
+  REQUIRE(!f.is_integer());
+  REQUIRE(!f.is_floating_point());
+  REQUIRE(f.is_blob());
+  REQUIRE(!f.is_bool());
+  REQUIRE(!f.is_string());
+
+  auto blob_val = f.as<utils::blob>();
+  REQUIRE(blob_val.has_value());
+  REQUIRE(blob_val.value() == utils::blob{ 7,8,6,5,4,3 });
+
+  REQUIRE_THROWS_AS(f.as<std::string>(), std::logic_error);
 }