Use std::optional if available.

Currently, SDK requires C++11 minimum.
So, boost::optional type is used for optional values.
For C++17 and above more convenient is to use std::optional instead.
This PR makes the optional type used configurable.

Suppress Linter complains.

Relates-To: NLAM-23
Signed-off-by: sopov <ext-alexander.sopov@here.com>

Author: asopov-here

olp-cpp-sdk-dataservice-read/include/olp/dataservice/read/CatalogRequest.h

@@ -46,7 +46,7 @@ class DATASERVICE_READ_API CatalogRequest final {
    * @return The `BillingTag` string or `olp::porting::none` if the billing tag
    * is not set.
    */
-  inline const olp::porting::optional<std::string>& GetBillingTag() const {
+  const olp::porting::optional<std::string>& GetBillingTag() const {
     return billing_tag_;
   }
 
@@ -59,7 +59,7 @@ class DATASERVICE_READ_API CatalogRequest final {
    *
    * @return A reference to the updated `CatalogRequest` instance.
    */
-  inline CatalogRequest& WithBillingTag(olp::porting::optional<std::string> tag) {
+  CatalogRequest& WithBillingTag(porting::optional<std::string> tag) {
     billing_tag_ = std::move(tag);
     return *this;
   }
@@ -74,7 +74,7 @@ class DATASERVICE_READ_API CatalogRequest final {
    *
    * @return A reference to the updated `CatalogRequest` instance.
    */
-  inline CatalogRequest& WithBillingTag(std::string&& tag) {
+  CatalogRequest& WithBillingTag(std::string&& tag) {
     billing_tag_ = std::move(tag);
     return *this;
   }
@@ -87,7 +87,7 @@ class DATASERVICE_READ_API CatalogRequest final {
    *
    * @return The fetch option.
    */
-  inline FetchOptions GetFetchOption() const { return fetch_option_; }
+  FetchOptions GetFetchOption() const { return fetch_option_; }
 
   /**
    * @brief Sets the fetch option that you can use to set the source from
@@ -99,7 +99,7 @@ class DATASERVICE_READ_API CatalogRequest final {
    *
    * @return A reference to the updated `CatalogVersionRequest` instance.
    */
-  inline CatalogRequest& WithFetchOption(FetchOptions fetch_option) {
+  CatalogRequest& WithFetchOption(const FetchOptions fetch_option) {
     fetch_option_ = fetch_option;
     return *this;
   }
@@ -109,7 +109,7 @@ class DATASERVICE_READ_API CatalogRequest final {
    *
    * @return A string representation of the request.
    */
-  inline std::string CreateKey() const {
+  std::string CreateKey() const {
     std::stringstream out;
     if (GetBillingTag()) {
       out << "$" << *GetBillingTag();
@@ -119,7 +119,7 @@ class DATASERVICE_READ_API CatalogRequest final {
   }
 
  private:
-  olp::porting::optional<std::string> billing_tag_;
+  porting::optional<std::string> billing_tag_;
   FetchOptions fetch_option_{OnlineIfNotFound};
 };
 

olp-cpp-sdk-dataservice-write/include/olp/dataservice/write/generated/model/Index.h

@@ -324,9 +324,9 @@ class DATASERVICE_WRITE_API Index final {
       : id_(std::move(uuid)), indexFields_(std::move(indexFields)) {}
 
  private:
-  olp::porting::optional<std::string> checksum_;
-  olp::porting::optional<std::map<std::string, std::string>> metadata_;
-  olp::porting::optional<int64_t> size_;
+  porting::optional<std::string> checksum_;
+  porting::optional<std::map<std::string, std::string>> metadata_;
+  porting::optional<int64_t> size_;
   std::string id_;
   std::map<IndexName, std::shared_ptr<IndexValue>> indexFields_;
 
@@ -336,14 +336,16 @@ class DATASERVICE_WRITE_API Index final {
    *
    * @return The checksum.
    */
-  const olp::porting::optional<std::string>& GetCheckSum() const { return checksum_; }
+  const porting::optional<std::string>& GetCheckSum() const {
+    return checksum_;
+  }
 
   /**
    * @brief Gets a mutable reference to the checksum of the index layer.
    *
    * @return The mutable reference to the checksum.
    */
-  olp::porting::optional<std::string>& GetMutableCheckSum() { return checksum_; }
+  porting::optional<std::string>& GetMutableCheckSum() { return checksum_; }
 
   /**
    * @brief Sets the checksum.
@@ -357,7 +359,7 @@ class DATASERVICE_WRITE_API Index final {
    *
    * @return The metadata of the index layer.
    */
-  const olp::porting::optional<std::map<std::string, std::string>>& GetMetadata()
+  const porting::optional<std::map<std::string, std::string>>& GetMetadata()
       const {
     return metadata_;
   }
@@ -367,7 +369,7 @@ class DATASERVICE_WRITE_API Index final {
    *
    * @return The mutable reference to the metadata.
    */
-  olp::porting::optional<std::map<std::string, std::string>>& GetMutableMetadata() {
+  porting::optional<std::map<std::string, std::string>>& GetMutableMetadata() {
     return metadata_;
   }
 
@@ -435,14 +437,14 @@ class DATASERVICE_WRITE_API Index final {
    *
    * @return The size of the index layer.
    */
-  const olp::porting::optional<int64_t>& GetSize() const { return size_; }
+  const porting::optional<int64_t>& GetSize() const { return size_; }
 
   /**
    * @brief Gets a mutable reference to the size of the index layer.
    *
    * @return The mutable reference to the size of the index layer.
    */
-  olp::porting::optional<int64_t>& GetMutableSize() { return size_; }
+  porting::optional<int64_t>& GetMutableSize() { return size_; }
 
   /**
    * @brief Sets the size of the index layer.