Issue 1066 (#1080)
Implemented `as<T>()` and `is<T>()` with accompanying tests
diff --git a/include/json/value.h b/include/json/value.h
index d0af711..bf4f9c4 100644
--- a/include/json/value.h
+++ b/include/json/value.h
@@ -412,6 +412,10 @@
bool isArray() const;
bool isObject() const;
+ /// The `as<T>` and `is<T>` member function templates and specializations.
+ template <typename T> T as() const = delete;
+ template <typename T> bool is() const = delete;
+
bool isConvertibleTo(ValueType other) const;
/// Number of values in array or object
@@ -673,6 +677,41 @@
ptrdiff_t limit_;
};
+template <> inline bool Value::as<bool>() const { return asBool(); }
+template <> inline bool Value::is<bool>() const { return isBool(); }
+
+template <> inline Int Value::as<Int>() const { return asInt(); }
+template <> inline bool Value::is<Int>() const { return isInt(); }
+
+template <> inline UInt Value::as<UInt>() const { return asUInt(); }
+template <> inline bool Value::is<UInt>() const { return isUInt(); }
+
+#if defined(JSON_HAS_INT64)
+template <> inline Int64 Value::as<Int64>() const { return asInt64(); }
+template <> inline bool Value::is<Int64>() const { return isInt64(); }
+
+template <> inline UInt64 Value::as<UInt64>() const { return asUInt64(); }
+template <> inline bool Value::is<UInt64>() const { return isUInt64(); }
+#endif
+
+template <> inline double Value::as<double>() const { return asDouble(); }
+template <> inline bool Value::is<double>() const { return isDouble(); }
+
+template <> inline String Value::as<String>() const { return asString(); }
+template <> inline bool Value::is<String>() const { return isString(); }
+
+/// These `as` specializations are type conversions, and do not have a
+/// corresponding `is`.
+template <> inline float Value::as<float>() const { return asFloat(); }
+template <> inline const char* Value::as<const char*>() const {
+ return asCString();
+}
+#ifdef JSON_USE_CPPTL
+template <> inline CppTL::ConstString Value::as<CppTL::ConstString>() const {
+ return asConstString();
+}
+#endif
+
/** \brief Experimental and untested: represents an element of the "path" to
* access a node.
*/
diff --git a/src/test_lib_json/main.cpp b/src/test_lib_json/main.cpp
index fff5b2c..c0cc00e 100644
--- a/src/test_lib_json/main.cpp
+++ b/src/test_lib_json/main.cpp
@@ -3502,6 +3502,53 @@
return runner.runCommandLine(argc, argv);
}
+struct MemberTemplateAs : JsonTest::TestCase {
+ template <typename T, typename F>
+ JsonTest::TestResult& EqEval(T v, F f) const {
+ const Json::Value j = v;
+ return JSONTEST_ASSERT_EQUAL(j.as<T>(), f(j));
+ }
+};
+
+JSONTEST_FIXTURE_LOCAL(MemberTemplateAs, BehavesSameAsNamedAs) {
+ const Json::Value jstr = "hello world";
+ JSONTEST_ASSERT_STRING_EQUAL(jstr.as<const char*>(), jstr.asCString());
+ JSONTEST_ASSERT_STRING_EQUAL(jstr.as<Json::String>(), jstr.asString());
+#ifdef JSON_USE_CPPTL
+ JSONTEST_ASSERT_STRING_EQUAL(js.as<CppTL::ConstString>(), js.asConstString());
+#endif
+ EqEval(Json::Int(64), [](const Json::Value& j) { return j.asInt(); });
+ EqEval(Json::UInt(64), [](const Json::Value& j) { return j.asUInt(); });
+#if defined(JSON_HAS_INT64)
+ EqEval(Json::Int64(64), [](const Json::Value& j) { return j.asInt64(); });
+ EqEval(Json::UInt64(64), [](const Json::Value& j) { return j.asUInt64(); });
+#endif // if defined(JSON_HAS_INT64)
+ EqEval(Json::LargestInt(64),
+ [](const Json::Value& j) { return j.asLargestInt(); });
+ EqEval(Json::LargestUInt(64),
+ [](const Json::Value& j) { return j.asLargestUInt(); });
+
+ EqEval(69.69f, [](const Json::Value& j) { return j.asFloat(); });
+ EqEval(69.69, [](const Json::Value& j) { return j.asDouble(); });
+ EqEval(false, [](const Json::Value& j) { return j.asBool(); });
+ EqEval(true, [](const Json::Value& j) { return j.asBool(); });
+}
+
+class MemberTemplateIs : public JsonTest::TestCase {};
+
+JSONTEST_FIXTURE_LOCAL(MemberTemplateIs, BehavesSameAsNamedIs) {
+ const Json::Value values[] = {true, 142, 40.63, "hello world"};
+ for (const Json::Value& j : values) {
+ JSONTEST_ASSERT_EQUAL(j.is<bool>(), j.isBool());
+ JSONTEST_ASSERT_EQUAL(j.is<Json::Int>(), j.isInt());
+ JSONTEST_ASSERT_EQUAL(j.is<Json::Int64>(), j.isInt64());
+ JSONTEST_ASSERT_EQUAL(j.is<Json::UInt>(), j.isUInt());
+ JSONTEST_ASSERT_EQUAL(j.is<Json::UInt64>(), j.isUInt64());
+ JSONTEST_ASSERT_EQUAL(j.is<double>(), j.isDouble());
+ JSONTEST_ASSERT_EQUAL(j.is<Json::String>(), j.isString());
+ }
+}
+
#if defined(__GNUC__)
#pragma GCC diagnostic pop
#endif