From b932b50414c806f2fa590a01ccf3cfd94d27165f Mon Sep 17 00:00:00 2001
From: Dan Goodliffe <dan@randomdan.homeip.net>
Date: Wed, 22 Aug 2018 19:47:53 +0100
Subject: Structured binding

Replace Row::value method with one that supports structured binding of
field values
---
 libdbpp/selectcommand.h              | 20 +++++++++++++++++++-
 libdbpp/selectcommandUtil.impl.h     |  7 +++++++
 libdbpp/unittests/libdbpp-postgresql |  2 +-
 libdbpp/unittests/testUtils.cpp      | 22 ++++++++++++++++++++--
 4 files changed, 47 insertions(+), 4 deletions(-)

diff --git a/libdbpp/selectcommand.h b/libdbpp/selectcommand.h
index 0d2a4ca..ee4c9ad 100644
--- a/libdbpp/selectcommand.h
+++ b/libdbpp/selectcommand.h
@@ -13,6 +13,12 @@
 #include <visibility.h>
 #include <exception.h>
 
+#ifndef BOOST_TEST_MODULE
+#define DEPRECATE __attribute__((deprecated))
+#else
+#define DEPRECATE
+#endif
+
 namespace DB {
 	class Column;
 	class SelectCommand;
@@ -38,7 +44,10 @@ namespace DB {
 
 			/// Get value of column C in current row.
 			template<unsigned int C>
-			typename std::tuple_element<C, std::tuple<Fn...>>::type value() const;
+			typename std::tuple_element<C, std::tuple<Fn...>>::type value() const DEPRECATE ;
+
+			template<unsigned int C>
+			typename std::tuple_element<C, std::tuple<Fn...>>::type get() const;
 	};
 
 	template<typename ... Fn>
@@ -137,5 +146,14 @@ namespace DB {
 	};
 }
 
+namespace std {
+	template<typename ... Fn> struct tuple_size<DB::Row<Fn...>> {
+		static constexpr auto value =  sizeof...(Fn);
+	};
+	template<size_t C, typename ... Fn> struct tuple_element<C, DB::Row<Fn...>> {
+		typedef typename std::tuple_element<C, std::tuple<Fn...>>::type type;
+	};
+}
+
 #endif
 
diff --git a/libdbpp/selectcommandUtil.impl.h b/libdbpp/selectcommandUtil.impl.h
index 6446de0..a6d17ca 100644
--- a/libdbpp/selectcommandUtil.impl.h
+++ b/libdbpp/selectcommandUtil.impl.h
@@ -92,6 +92,13 @@ namespace DB {
 	template<typename ... Fn>
 	template<unsigned int C>
 	inline typename std::tuple_element<C, std::tuple<Fn...>>::type Row<Fn...>::value() const
+	{
+		return get<C>();
+	}
+
+	template<typename ... Fn>
+	template<unsigned int C>
+	inline typename std::tuple_element<C, std::tuple<Fn...>>::type Row<Fn...>::get() const
 	{
 		typename std::tuple_element<C, std::tuple<Fn...>>::type a;
 		sel->operator[](C) >> a;
diff --git a/libdbpp/unittests/libdbpp-postgresql b/libdbpp/unittests/libdbpp-postgresql
index f6686d1..a4c6328 160000
--- a/libdbpp/unittests/libdbpp-postgresql
+++ b/libdbpp/unittests/libdbpp-postgresql
@@ -1 +1 @@
-Subproject commit f6686d1bf35611b779189f80b460790708094895
+Subproject commit a4c6328efab2e614a46b4a1c78fb0c5678c3fd76
diff --git a/libdbpp/unittests/testUtils.cpp b/libdbpp/unittests/testUtils.cpp
index 04fad4f..30d5bc4 100644
--- a/libdbpp/unittests/testUtils.cpp
+++ b/libdbpp/unittests/testUtils.cpp
@@ -65,9 +65,27 @@ BOOST_AUTO_TEST_CASE( stdforOverRows )
 		count += 1;
 		BOOST_REQUIRE_EQUAL("a", row[0].name);
 		BOOST_REQUIRE_EQUAL(1, row["c"].colNo);
+		// Test old function
 		int64_t a = row.value<0>();
 		totalOfa += a;
-		totalOfc += row.value<1>();
+		totalOfc += row.get<1>();
+	}
+	BOOST_REQUIRE_EQUAL(count, 2);
+	BOOST_REQUIRE_EQUAL(totalOfa, 3);
+	BOOST_REQUIRE_EQUAL(totalOfc, "Some textSome text");
+}
+
+BOOST_AUTO_TEST_CASE( stdforOverRowsStructuredBinding )
+{
+	auto db = DB::MockDatabase::openConnectionTo("pqmock");
+	unsigned int count = 0;
+	int64_t totalOfa = 0;
+	std::string totalOfc;
+	auto sel = db->select("SELECT a, c FROM forEachRow ORDER BY a DESC");
+	for (const auto [ a, c ] : sel->as<int64_t, std::string>()) {
+		count += 1;
+		totalOfa += a;
+		totalOfc += c;
 	}
 	BOOST_REQUIRE_EQUAL(count, 2);
 	BOOST_REQUIRE_EQUAL(totalOfa, 3);
@@ -262,7 +280,7 @@ BOOST_AUTO_TEST_CASE( bindIntPtr )
 
 BOOST_AUTO_TEST_CASE( testBlobRaw )
 {
-	DB::Blob ptr(this, 1);	
+	DB::Blob ptr(this, 1);
 	BOOST_REQUIRE_EQUAL(ptr.data, this);
 	BOOST_REQUIRE_EQUAL(ptr.len, 1);
 }
-- 
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