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ArduinoJson/src/ArduinoJson/Operators/VariantOr.hpp
2018-11-30 17:53:54 +01:00

50 lines
1.4 KiB
C++

// ArduinoJson - arduinojson.org
// Copyright Benoit Blanchon 2014-2018
// MIT License
#pragma once
#include "../Polyfills/attributes.hpp"
#include "../Polyfills/type_traits.hpp"
#include "../Variant/VariantAs.hpp"
namespace ARDUINOJSON_NAMESPACE {
template <typename TImpl>
class VariantOr {
public:
// Returns the default value if the VariantRef is undefined of incompatible
template <typename T>
typename enable_if<!is_integral<T>::value, T>::type operator|(
const T &defaultValue) const {
if (impl()->template is<T>())
return impl()->template as<T>();
else
return defaultValue;
}
// Returns the default value if the VariantRef is undefined of incompatible
// Special case for string: null is treated as undefined
const char *operator|(const char *defaultValue) const {
const char *value = impl()->template as<const char *>();
return value ? value : defaultValue;
}
// Returns the default value if the VariantRef is undefined of incompatible
// Special case for integers: we also accept double
template <typename Integer>
typename enable_if<is_integral<Integer>::value, Integer>::type operator|(
const Integer &defaultValue) const {
if (impl()->template is<double>())
return impl()->template as<Integer>();
else
return defaultValue;
}
private:
const TImpl *impl() const {
return static_cast<const TImpl *>(this);
}
};
} // namespace ARDUINOJSON_NAMESPACE