Commit 8bde3be1 authored by Philipp A. Hartmann's avatar Philipp A. Hartmann

GenericValue: add copy constructor and CopyFrom

To allow deep copying from an existing GenericValue, an
explicit "copy constructor" (with required Allocator param)
and an "CopyFrom" assignment function are added.

  Document d; Document::AllocatorType& a = d.GetAllocator();
  Value v1("foo");
  // Value v2(v1); // not allowed

  Value v2(v1,a);                             // make a copy
  RAPIDJSON_ASSERT(v1.IsString());            // v1 untouched
  d.SetArray().PushBack(v1,a).PushBack(v2,a);
  RAPIDJSON_ASSERT(v1.Empty() && v2.Empty());

  v2.CopyFrom(d,a);                           // copy whole document
  RAPIDJSON_ASSERT(d.IsArray() && d.Size());  // d untouched
  v1.SetObject().AddMember( "array", v2, a );
  d.PushBack(v1,a);

Additionally, the Handler implementation in GenericDocument is made
private again, restricting access to GenericReader and GenericValue.
parent a0e5e68f
......@@ -69,6 +69,16 @@ public:
flags_ = defaultFlags[type];
}
//! Explicit copy constructor (with allocator)
/*! Creates a copy of a Value by using the given Allocator
\tparam SourceAllocator allocator of \c rhs
\param rhs Value to copy from (read-only)
\param allocator Allocator to use for copying
\see CopyFrom()
*/
template< typename SourceAllocator >
GenericValue(const GenericValue<Encoding,SourceAllocator>& rhs, Allocator & allocator);
//! Constructor for boolean value.
explicit GenericValue(bool b) : flags_(b ? kTrueFlag : kFalseFlag) {}
......@@ -183,6 +193,21 @@ public:
new (this) GenericValue(value);
return *this;
}
//! Deep-copy assignment from Value
/*! Assigns a \b copy of the Value to the current Value object
\tparam SourceAllocator Allocator type of \c rhs
\param rhs Value to copy from (read-only)
\param allocator Allocator to use for copying
*/
template <typename SourceAllocator>
GenericValue& CopyFrom(const GenericValue<Encoding,SourceAllocator>& rhs, Allocator& allocator) {
RAPIDJSON_ASSERT((void*)this != (void*)&rhs);
this->~GenericValue();
new (this) GenericValue(rhs,allocator);
return *this;
}
//@}
//!@name Type
......@@ -840,8 +865,10 @@ public:
//! Get the capacity of stack in bytes.
size_t GetStackCapacity() const { return stack_.GetCapacity(); }
//private:
//friend class GenericReader<Encoding>; // for Reader to call the following private handler functions
private:
// callers of the following private Handler functions
template <typename,typename,typename> friend class GenericReader; // for parsing
friend class GenericValue<Encoding,Allocator>; // for deep copying
// Implementation of Handler
void Null() { new (stack_.template Push<ValueType>()) ValueType(); }
......@@ -893,6 +920,17 @@ private:
typedef GenericDocument<UTF8<> > Document;
// defined here due to the dependency on GenericDocument
template <typename Encoding, typename Allocator>
template <typename SourceAllocator>
inline
GenericValue<Encoding,Allocator>::GenericValue(const GenericValue<Encoding,SourceAllocator>& rhs, Allocator& allocator)
{
GenericDocument<Encoding,Allocator> d(&allocator);
rhs.Accept(d);
RawAssign(*d.stack_.template Pop<GenericValue>(1));
}
} // namespace rapidjson
#ifdef _MSC_VER
......
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