Enable Ort objects to be stored in a resizable std::vector (#22608)

### Description
<!-- Describe your changes. -->
Allow some classes to be default constructed.
The effect is the same as constructing it with nullptr.
Make default ctor visible from the base classes.

### Motivation and Context
<!-- - Why is this change required? What problem does it solve?
- If it fixes an open issue, please link to the issue here. -->
Multiple customers complained that when storing Ort::Value
in an instance of std::vector, vector can not be resized.

We enable that with allowing it default constructed.

include/onnxruntime/core/session/onnxruntime_cxx_api.h

@@ -650,6 +650,9 @@ using AllocatedStringPtr = std::unique_ptr<char, detail::AllocatedFree>;
  *  constructors to construct an instance of a Status object from exceptions.
  */
 struct Status : detail::Base<OrtStatus> {
+  using Base = detail::Base<OrtStatus>;
+  using Base::Base;
+
   explicit Status(std::nullptr_t) noexcept {}               ///< Create an empty object, must be assigned a valid one to be used
   explicit Status(OrtStatus* status) noexcept;              ///< Takes ownership of OrtStatus instance returned from the C API.
   explicit Status(const Exception&) noexcept;               ///< Creates status instance out of exception
@@ -728,6 +731,9 @@ struct Env : detail::Base<OrtEnv> {
  *
  */
 struct CustomOpDomain : detail::Base<OrtCustomOpDomain> {
+  using Base = detail::Base<OrtCustomOpDomain>;
+  using Base::Base;
+
   explicit CustomOpDomain(std::nullptr_t) {}  ///< Create an empty CustomOpDomain object, must be assigned a valid one to be used
 
   /// \brief Wraps OrtApi::CreateCustomOpDomain
@@ -963,8 +969,10 @@ struct SessionOptions : detail::SessionOptionsImpl<OrtSessionOptions> {
  *
  */
 struct ModelMetadata : detail::Base<OrtModelMetadata> {
-  explicit ModelMetadata(std::nullptr_t) {}                                   ///< Create an empty ModelMetadata object, must be assigned a valid one to be used
-  explicit ModelMetadata(OrtModelMetadata* p) : Base<OrtModelMetadata>{p} {}  ///< Used for interop with the C API
+  using Base = detail::Base<OrtModelMetadata>;
+  using Base::Base;
+
+  explicit ModelMetadata(std::nullptr_t) {}  ///< Create an empty ModelMetadata object, must be assigned a valid one to be used
 
   /** \brief Returns a copy of the producer name.
    *
@@ -1237,6 +1245,9 @@ using ConstTensorTypeAndShapeInfo = detail::TensorTypeAndShapeInfoImpl<detail::U
  *
  */
 struct TensorTypeAndShapeInfo : detail::TensorTypeAndShapeInfoImpl<OrtTensorTypeAndShapeInfo> {
+  using Base = detail::TensorTypeAndShapeInfoImpl<OrtTensorTypeAndShapeInfo>;
+  using Base::Base;
+
   explicit TensorTypeAndShapeInfo(std::nullptr_t) {}                                                ///< Create an empty TensorTypeAndShapeInfo object, must be assigned a valid one to be used
   explicit TensorTypeAndShapeInfo(OrtTensorTypeAndShapeInfo* p) : TensorTypeAndShapeInfoImpl{p} {}  ///< Used for interop with the C API
   ConstTensorTypeAndShapeInfo GetConst() const { return ConstTensorTypeAndShapeInfo{this->p_}; }
@@ -1258,6 +1269,9 @@ using ConstSequenceTypeInfo = detail::SequenceTypeInfoImpl<detail::Unowned<const
  *
  */
 struct SequenceTypeInfo : detail::SequenceTypeInfoImpl<OrtSequenceTypeInfo> {
+  using Base = detail::SequenceTypeInfoImpl<OrtSequenceTypeInfo>;
+  using Base::Base;
+
   explicit SequenceTypeInfo(std::nullptr_t) {}                                                         ///< Create an empty SequenceTypeInfo object, must be assigned a valid one to be used
   explicit SequenceTypeInfo(OrtSequenceTypeInfo* p) : SequenceTypeInfoImpl<OrtSequenceTypeInfo>{p} {}  ///< Used for interop with the C API
   ConstSequenceTypeInfo GetConst() const { return ConstSequenceTypeInfo{this->p_}; }
@@ -1293,6 +1307,9 @@ using ConstMapTypeInfo = detail::MapTypeInfoImpl<detail::Unowned<const OrtMapTyp
  *
  */
 struct MapTypeInfo : detail::MapTypeInfoImpl<OrtMapTypeInfo> {
+  using Base = detail::MapTypeInfoImpl<OrtMapTypeInfo>;
+  using Base::Base;
+
   explicit MapTypeInfo(std::nullptr_t) {}                                          ///< Create an empty MapTypeInfo object, must be assigned a valid one to be used
   explicit MapTypeInfo(OrtMapTypeInfo* p) : MapTypeInfoImpl<OrtMapTypeInfo>{p} {}  ///< Used for interop with the C API
   ConstMapTypeInfo GetConst() const { return ConstMapTypeInfo{this->p_}; }
@@ -1324,6 +1341,9 @@ using ConstTypeInfo = detail::TypeInfoImpl<detail::Unowned<const OrtTypeInfo>>;
 /// the information about contained sequence or map depending on the ONNXType.
 /// </summary>
 struct TypeInfo : detail::TypeInfoImpl<OrtTypeInfo> {
+  using Base = detail::TypeInfoImpl<OrtTypeInfo>;
+  using Base::Base;
+
   explicit TypeInfo(std::nullptr_t) {}                                 ///< Create an empty TypeInfo object, must be assigned a valid one to be used
   explicit TypeInfo(OrtTypeInfo* p) : TypeInfoImpl<OrtTypeInfo>{p} {}  ///< C API Interop
 
@@ -1661,11 +1681,11 @@ using UnownedValue = detail::ValueImpl<detail::Unowned<OrtValue>>;
  */
 struct Value : detail::ValueImpl<OrtValue> {
   using Base = detail::ValueImpl<OrtValue>;
+  using Base::Base;
   using OrtSparseValuesParam = detail::OrtSparseValuesParam;
   using Shape = detail::Shape;
 
-  explicit Value(std::nullptr_t) {}         ///< Create an empty Value object, must be assigned a valid one to be used
-  explicit Value(OrtValue* p) : Base{p} {}  ///< Used for interop with the C API
+  explicit Value(std::nullptr_t) {}  ///< Create an empty Value object, must be assigned a valid one to be used
   Value(Value&&) = default;
   Value& operator=(Value&&) = default;
 
@@ -1941,6 +1961,10 @@ struct ArenaCfg : detail::Base<OrtArenaCfg> {
 /// This struct provides life time management for custom op attribute
 /// </summary>
 struct OpAttr : detail::Base<OrtOpAttr> {
+  using Base = detail::Base<OrtOpAttr>;
+  using Base::Base;
+
+  explicit OpAttr(std::nullptr_t) {}
   OpAttr(const char* name, const void* data, int len, OrtOpAttrType type);
 };
 
@@ -2183,6 +2207,8 @@ using ConstKernelInfo = detail::KernelInfoImpl<detail::Unowned<const OrtKernelIn
 /// so it does not destroy the pointer the kernel does not own.
 /// </summary>
 struct KernelInfo : detail::KernelInfoImpl<OrtKernelInfo> {
+  using Base = detail::KernelInfoImpl<OrtKernelInfo>;
+  using Base::Base;
   explicit KernelInfo(std::nullptr_t) {}     ///< Create an empty instance to initialize later
   explicit KernelInfo(OrtKernelInfo* info);  ///< Take ownership of the instance
   ConstKernelInfo GetConst() const { return ConstKernelInfo{this->p_}; }
@@ -2192,6 +2218,9 @@ struct KernelInfo : detail::KernelInfoImpl<OrtKernelInfo> {
 /// Create and own custom defined operation.
 /// </summary>
 struct Op : detail::Base<OrtOp> {
+  using Base = detail::Base<OrtOp>;
+  using Base::Base;
+
   explicit Op(std::nullptr_t) {}  ///< Create an empty Operator object, must be assigned a valid one to be used
 
   explicit Op(OrtOp*);  ///< Take ownership of the OrtOp

include/onnxruntime/core/session/onnxruntime_cxx_inline.h

@@ -51,7 +51,7 @@ inline void ThrowOnError(const Status& st) {
   }
 }
 
-inline Status::Status(OrtStatus* status) noexcept : Base<OrtStatus>{status} {
+inline Status::Status(OrtStatus* status) noexcept : detail::Base<OrtStatus>{status} {
 }
 
 inline Status::Status(const std::exception& e) noexcept {
@@ -1908,7 +1908,7 @@ inline void attr_utils::GetAttrs(const OrtKernelInfo* p, const char* name, std::
 
 inline KernelInfo::KernelInfo(OrtKernelInfo* info) : detail::KernelInfoImpl<OrtKernelInfo>{info} {}
 
-inline Op::Op(OrtOp* p) : Base<OrtOp>(p) {}
+inline Op::Op(OrtOp* p) : detail::Base<OrtOp>(p) {}
 
 inline Op Op::Create(const OrtKernelInfo* info, const char* op_name, const char* domain, int version,
                      const char** type_constraint_names,

onnxruntime/test/shared_lib/test_nontensor_types.cc

@@ -987,6 +987,32 @@ TEST(CApiTest, SparseTensorFillSparseTensorFormatAPI) {
   }
 }
 
+TEST(CApi, TestResize) {
+  std::vector<Ort::Value> values;
+  values.resize(10);
+
+  std::vector<Ort::Status> sts;
+  sts.resize(5);
+
+  std::vector<Ort::CustomOpDomain> domains;
+  domains.resize(5);
+
+  std::vector<Ort::TensorTypeAndShapeInfo> type_and_shape;
+  type_and_shape.resize(5);
+
+  std::vector<Ort::SequenceTypeInfo> seq_type_info;
+  seq_type_info.resize(5);
+
+  std::vector<Ort::MapTypeInfo> map_type_info;
+  map_type_info.resize(5);
+
+  std::vector<Ort::TypeInfo> type_info;
+  type_info.resize(5);
+
+  std::vector<Ort::OpAttr> op_attr;
+  op_attr.resize(5);
+}
+
 TEST(CApiTest, SparseTensorFillSparseFormatStringsAPI) {
   auto allocator = Ort::AllocatorWithDefaultOptions();
   Ort::MemoryInfo info("Cpu", OrtDeviceAllocator, 0, OrtMemTypeDefault);