64 lines
2.1 KiB
Plaintext
64 lines
2.1 KiB
Plaintext
#ifndef OSGINTROSPECTION_VARIANT_CAST_
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#define OSGINTROSPECTION_VARIANT_CAST_
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#include <osgIntrospection/Value>
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#include <osgIntrospection/ReaderWriter>
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#include <sstream>
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namespace osgIntrospection
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{
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/// Tries to convert an instance of Value to an object of type T.
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/// If T is a plain type or a pointer type (either const or non-const),
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/// and it matches the type of the value contained in v, then the actual
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/// value of type T is returned. If T is a [const] reference type, and
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/// its base (non reference) type matches the internal value's type,
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/// then a [const] reference to the internal value is returned.
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/// If none of the above conditions are met, a conversion is attempted
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/// as described in Value::convert() and then variant_cast is called again
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/// with the converted value as parameter.
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/// If the conversion can't be completed, an exception is thrown.
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/// Conversions that attempt to make a const pointer non-const will fail.
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template<typename T> T variant_cast(const Value &v)
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{
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// return value
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Value::Instance<T> *i = dynamic_cast<Value::Instance<T> *>(v.inbox_->inst_);
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if (i) return i->data_;
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// return reference to value
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i = dynamic_cast<Value::Instance<T> *>(v.inbox_->ref_inst_);
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if (i) return i->data_;
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// return const reference to value
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i = dynamic_cast<Value::Instance<T> *>(v.inbox_->const_ref_inst_);
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if (i) return i->data_;
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// try to convert v to type T and restart
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return variant_cast<T>(v.convertTo(typeof(T)));
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}
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/// Returns a typed pointer to the data contained in a Value
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/// instance. If the value's type is not identical to type T,
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/// a null pointer is returned.
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template<typename T> T *extract_raw_data(Value &v)
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{
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Value::Instance<T> *i = dynamic_cast<Value::Instance<T> *>(v.inbox_->inst_);
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if (i) return &i->data_;
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return 0;
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}
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/// Returns a typed pointer to the data contained in a const Value
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/// instance. If the value's type is not identical to type T, a
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/// null pointer is returned.
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template<typename T> const T *extract_raw_data(const Value &v)
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{
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Value::Instance<T> *i = dynamic_cast<Value::Instance<T> *>(v.inbox_->inst_);
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if (i) return &i->data_;
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return 0;
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}
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}
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#endif
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