Solved #597.

Added `std::optional` and `std::string_view` adaptors.

test/msgpack_cpp17.cpp

@@ -0,0 +1,207 @@
+#include <msgpack.hpp>
+
+#include <gtest/gtest.h>
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#if !defined(MSGPACK_USE_CPP03) && __cplusplus >= 201703
+
+// C++17
+
+TEST(MSGPACK_CPP17, optional_pack_convert_nil)
+{
+    std::stringstream ss;
+    std::optional<int> val1;
+    msgpack::pack(ss, val1);
+    msgpack::object_handle oh =
+        msgpack::unpack(ss.str().data(), ss.str().size());
+    std::optional<int> val2 = oh.get().as<std::optional<int> >();
+    EXPECT_TRUE(val1 == val2);
+}
+
+TEST(MSGPACK_CPP17, optional_pack_convert_int)
+{
+    std::stringstream ss;
+    std::optional<int> val1 = 1;
+    msgpack::pack(ss, val1);
+    msgpack::object_handle oh =
+        msgpack::unpack(ss.str().data(), ss.str().size());
+    std::optional<int> val2 = oh.get().as<std::optional<int> >();
+    EXPECT_TRUE(val1 == val2);
+}
+
+TEST(MSGPACK_CPP17, optional_pack_convert_vector)
+{
+    typedef std::optional<std::vector<int> > ovi_t;
+    std::stringstream ss;
+    ovi_t val1;
+    std::vector<int> v;
+    v.push_back(1);
+    v.push_back(2);
+    v.push_back(3);
+    val1 = v;
+    msgpack::pack(ss, val1);
+    msgpack::object_handle oh =
+        msgpack::unpack(ss.str().data(), ss.str().size());
+    ovi_t  val2 = oh.get().as<ovi_t>();
+    EXPECT_TRUE(val1 == val2);
+}
+
+TEST(MSGPACK_CPP17, optional_pack_convert_vector_optional)
+{
+    typedef std::vector<std::optional<int> > voi_t;
+    std::stringstream ss;
+    voi_t val1;
+    val1.resize(3);
+    val1[0] = 1;
+    val1[2] = 3;
+    msgpack::pack(ss, val1);
+    msgpack::object_handle oh =
+        msgpack::unpack(ss.str().data(), ss.str().size());
+    voi_t  val2 = oh.get().as<voi_t>();
+    EXPECT_TRUE(val1 == val2);
+}
+
+TEST(MSGPACK_CPP17, optional_object_nil)
+{
+    std::optional<int> val1;
+    msgpack::object obj(val1);
+    std::optional<int> val2 = obj.as<std::optional<int> >();
+    EXPECT_TRUE(val1 == val2);
+}
+
+TEST(MSGPACK_CPP17, optional_object_int)
+{
+    std::optional<int> val1 = 1;
+    msgpack::object obj(val1);
+    std::optional<int> val2 = obj.as<std::optional<int> >();
+    EXPECT_TRUE(val1 == val2);
+}
+
+// Compile error as expected
+/*
+  TEST(MSGPACK_CPP17, optional_object_vector)
+  {
+  typedef std::optional<std::vector<int> > ovi_t;
+  ovi_t val1;
+  std::vector<int> v;
+  v.push_back(1);
+  v.push_back(2);
+  v.push_back(3);
+  val1 = v;
+  msgpack::object obj(val1);
+  ovi_t  val2 = obj.as<ovi_t>();
+  EXPECT_TRUE(val1 == val2);
+  }
+*/
+
+TEST(MSGPACK_CPP17, optional_object_with_zone_nil)
+{
+    msgpack::zone z;
+    std::optional<int> val1;
+    msgpack::object obj(val1, z);
+    std::optional<int> val2 = obj.as<std::optional<int> >();
+    EXPECT_TRUE(val1 == val2);
+}
+
+TEST(MSGPACK_CPP17, optional_object_with_zone_int)
+{
+    msgpack::zone z;
+    std::optional<int> val1 = 1;
+    msgpack::object obj(val1, z);
+    std::optional<int> val2 = obj.as<std::optional<int> >();
+    EXPECT_TRUE(val1 == val2);
+}
+
+TEST(MSGPACK_CPP17, optional_object_with_zone_vector_optional)
+{
+    typedef std::vector<std::optional<int> > voi_t;
+    msgpack::zone z;
+    voi_t val1;
+    val1.resize(3);
+    val1[0] = 1;
+    val1[2] = 3;
+    msgpack::object obj(val1, z);
+    voi_t  val2 = obj.as<voi_t>();
+    EXPECT_TRUE(val1 == val2);
+}
+
+struct no_def_con {
+    no_def_con() = delete;
+    no_def_con(int i):i(i) {}
+    int i;
+    MSGPACK_DEFINE(i);
+};
+
+inline bool operator==(no_def_con const& lhs, no_def_con const& rhs) {
+    return lhs.i == rhs.i;
+}
+
+inline bool operator!=(no_def_con const& lhs, no_def_con const& rhs) {
+    return !(lhs == rhs);
+}
+
+namespace msgpack {
+MSGPACK_API_VERSION_NAMESPACE(MSGPACK_DEFAULT_API_NS) {
+namespace adaptor {
+
+template <>
+struct as<no_def_con> {
+    no_def_con operator()(msgpack::object const& o) const {
+        if (o.type != msgpack::type::ARRAY) throw msgpack::type_error();
+        if (o.via.array.size != 1) throw msgpack::type_error();
+        return no_def_con(o.via.array.ptr[0].as<int>());
+    }
+};
+
+} // adaptor
+} // MSGPACK_API_VERSION_NAMESPACE(MSGPACK_DEFAULT_API_NS)
+} // msgpack
+
+TEST(MSGPACK_CPP17, optional_pack_convert_no_def_con)
+{
+    std::stringstream ss;
+    std::optional<no_def_con> val1 = no_def_con(1);
+    msgpack::pack(ss, val1);
+    msgpack::object_handle oh =
+        msgpack::unpack(ss.str().data(), ss.str().size());
+    std::optional<no_def_con> val2 = oh.get().as<std::optional<no_def_con>>();
+    EXPECT_TRUE(val1 == val2);
+}
+
+TEST(MSGPACK_CPP17, string_view_pack_convert_string_view)
+{
+    std::stringstream ss;
+    std::string s = "ABC";
+    std::string_view val1(s);
+
+    msgpack::pack(ss, val1);
+
+    msgpack::object_handle oh;
+    msgpack::unpack(oh, ss.str().data(), ss.str().size());
+    std::string_view val2 = oh.get().as<std::string_view>();
+    EXPECT_TRUE(val1 == val2);
+}
+
+TEST(MSGPACK_CPP17, string_view_object_strinf_view)
+{
+    std::string s = "ABC";
+    std::string_view val1(s);
+    msgpack::object obj(val1);
+    std::string_view val2 = obj.as<std::string_view>();
+    EXPECT_TRUE(val1 == val2);
+}
+
+TEST(MSGPACK_CPP17, string_view_object_with_zone_string_view)
+{
+    msgpack::zone z;
+    std::string s = "ABC";
+    std::string_view val1(s);
+    msgpack::object obj(val1, z);
+    std::string_view val2 = obj.as<std::string_view>();
+    EXPECT_TRUE(val1 == val2);
+}
+
+#endif // !defined(MSGPACK_USE_CPP03) && __cplusplus >= 201703