Added overflow handling in JsonVariant::as<T>() and JsonVariant::is<T>()

src/ArduinoJson/Numbers/convertNumber.hpp

@@ -0,0 +1,105 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2019
+// MIT License
+
+#pragma once
+
+#if defined(__clang__)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wconversion"
+#elif defined(__GNUC__)
+#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6)
+#pragma GCC diagnostic push
+#endif
+#pragma GCC diagnostic ignored "-Wconversion"
+#endif
+
+#include "../Polyfills/limits.hpp"
+#include "Float.hpp"
+#include "FloatTraits.hpp"
+#include "Integer.hpp"
+
+namespace ARDUINOJSON_NAMESPACE {
+
+template <typename TOut, typename TIn>
+typename enable_if<is_integral<TOut>::value && sizeof(TOut) <= sizeof(TIn),
+                   bool>::type
+canStorePositiveInteger(TIn value) {
+  return value <= TIn(numeric_limits<TOut>::highest());
+}
+
+template <typename TOut, typename TIn>
+typename enable_if<is_integral<TOut>::value && sizeof(TIn) < sizeof(TOut),
+                   bool>::type
+canStorePositiveInteger(TIn) {
+  return true;
+}
+
+template <typename TOut, typename TIn>
+typename enable_if<is_floating_point<TOut>::value, bool>::type
+canStorePositiveInteger(TIn) {
+  return true;
+}
+
+template <typename TOut, typename TIn>
+typename enable_if<is_floating_point<TOut>::value, bool>::type
+canStoreNegativeInteger(TIn) {
+  return true;
+}
+
+template <typename TOut, typename TIn>
+typename enable_if<is_integral<TOut>::value && is_signed<TOut>::value &&
+                       sizeof(TOut) <= sizeof(TIn),
+                   bool>::type
+canStoreNegativeInteger(TIn value) {
+  return value <= TIn(numeric_limits<TOut>::highest()) + 1;
+}
+
+template <typename TOut, typename TIn>
+typename enable_if<is_integral<TOut>::value && is_signed<TOut>::value &&
+                       sizeof(TIn) < sizeof(TOut),
+                   bool>::type
+canStoreNegativeInteger(TIn) {
+  return true;
+}
+
+template <typename TOut, typename TIn>
+typename enable_if<is_integral<TOut>::value && is_unsigned<TOut>::value,
+                   bool>::type
+canStoreNegativeInteger(TIn) {
+  return false;
+}
+
+template <typename TOut, typename TIn>
+TOut convertPositiveInteger(TIn value) {
+  return canStorePositiveInteger<TOut>(value) ? TOut(value) : 0;
+}
+
+template <typename TOut, typename TIn>
+TOut convertNegativeInteger(TIn value) {
+  return canStoreNegativeInteger<TOut>(value) ? TOut(~value + 1) : 0;
+}
+
+template <typename TOut, typename TIn>
+typename enable_if<is_floating_point<TOut>::value, TOut>::type convertFloat(
+    TIn value) {
+  return TOut(value);
+}
+
+template <typename TOut, typename TIn>
+typename enable_if<!is_floating_point<TOut>::value, TOut>::type convertFloat(
+    TIn value) {
+  return value >= numeric_limits<TOut>::lowest() &&
+                 value <= numeric_limits<TOut>::highest()
+             ? TOut(value)
+             : 0;
+}
+}  // namespace ARDUINOJSON_NAMESPACE
+
+#if defined(__clang__)
+#pragma clang diagnostic pop
+#elif defined(__GNUC__)
+#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6)
+#pragma GCC diagnostic pop
+#endif
+#endif